The main thing I would want to do is get custody BUT it doesn’t sound like you’re ready for that as you state many times how you guys have him a lot and that you feel like a built in babysitter (I would never feel like a babysitter to my kids or kids that I love like my own). Hopefully I’m wrong because he needs a very stable routine. This is the main thing they tell you about kids with adhd and it’s true. If he were your biological child how would you handle it? I think he needs a therapist for starters… maybe a psychiatrist. He’s only 9 and is probably struggling internally with everything more than you know or see. My 10yr old has ADHD and hasn’t been medicated for a long time. He doesn’t have the anger issues, but he has to stay on a very structured routine. Maybe he’s “stealing snacks” cause he’s hungry. I don’t see how it’s stealing when it’s FOOD from his house though. Maybe you and dad should talk to his Dr and have him tell you what it’s like to have adhd. Knowledge is power and will help you communicate with him better. Good luck. Don’t give up on him.
You go to social services to get this child assistance
Then you get a lawyer and fight for custody. Dad standing around wringing his hands is no excuse. He knows what to do. He just has to do it.
He needs a therapist
I have an almost 9 year old with autism and ADHD. I also have adult friends who have ADHD as well as their children. They NEED structure and routine first of all. Kids with neurodivergencies thrive with structure and routine because mentally they can plan on what’s going to happen and be prepared for that. Bouncing from house to house, the major differences in attention and daily routines etc is wreaking havoc on his brain, causing him to act out.
First all caregivers need to get on the same page in terms of when he is where, discipline, and regular daily routine.
Also, he needs therapy. Talk therapy and in home behavioral therapy are the 2 I would seriously recommend.
I don’t know how much you know about ADHD and how kids with ADHD brains work, but I highly suggest doing research and talking to adults that have it to get a better understanding.
Ultimately he’s acting out for valid reasons. His needs are not being met, such as hiding and hoarding food is the top sign that he is experiencing food instability somewhere. But his needs just aren’t being met as a whole, his brain is chaos and he nothing reliable in his life (example is knowing he’s at moms 5 days a weeks and dads 2 days a week. Or knowing that he can get away with something at moms but not at dads).
Get the poor help in anyway you can, and try not to take his behavior personally and do your best to create a safe home environment for all children in the home.
I would also suggest, based on this post, to start documenting all the days he is with you, from what hours to what hours, the condition he arrived and left in, comments he makes like if he says he’s hungry within an hour of getting to your place because he didn’t eat yet (example), negative behaviors you see an increase in after he comes back from mom’s etc. Document everything you can, take time/date stamped photos of him being really dirty/dressed inappropriately. Mark the weather conditions on those photos. And take mom to court for full custody.
Keep him as often as possible. Make sure he knows his place in your home and that he is welcome there. Make an effort to show him he is not a burden and your home is his home too. Offer the Mom to take him on a full time basis if she is “struggling”. Make sure he has a room or a space that is his in your home just like the other children have. He needs somewhere that he feels like he belongs, that he is loved unconditionally, that he is accepted and that he is wanted. Counseling or therapy may help but I would consider family therapy rather than individual so that he doesn’t feel like he is the problem. You are not a babysitter, you lost that title when you chose a relationship with his father. You play an important role in his life, you are his stepmother. Take pride in that and love him through the tough times. His appreciation will come later !
Check out ADDitude - they have tons of great articles and tips for dealing with difficult ADHD children. (I myself suffer from adhd, as does my 14 year old daughter, so I know how difficult this whole situation can be.)
He’s seeking for attentionin any way that he can get it because of the lack of it he gets with his bio mom. (We go through similar issues with my youngest sister.) he feels safe enough to act this way around you guys, because that’s his way of calling for help/attention. As children they don’t always know how to process their emotions, let alone get them out properly. Counseling is never a bad thing, any and everyone could benefit from counseling whether they have mental health problems, etc. I would suggest counseling, and continuing to do what you’re doing. Maybe sit down and talk with him, explain to him that he doesn’t have to act these ways to get love or attention. Maybe dad needs to do things with just him every so often. Best wishes to you guys 
and to whoever said you sounded more interested in his benefits, I don’t think that at all. You stating that she gets all of these benefits for him, yet you not being able to use said benefits to help him is frustrating.
I think getting him in therapy and if his life at his moms is that unstable yall could try to file emergency custody. Kinda sounds like he has ODD (Oppositional Defiant Disorder). Go read about it and see what you think. He is definitely searching for love and attention, regardless of the type of attention. Just keep loving him and showing him you want him there with your family. Best of luck 
Take her to court and take him from her. Counseling with you and dad and by his self beat of luck
Maybe he & dad need some one on one, he is pushed between 2 homes from a broken home. Yup he doesn’t know where he belongs , can be pretty upsetting for a 9 yr old. Understanding and love is what he needs.
His life sounds traumatic. He has expressed his pain and anger at not being his dads only. You said his mom isn’t around much either. Kid definitely needs therapy and SO MUCH LOVE
Seek therapy and be aware of what he is doing and especially to smaller children. Many times as these behaviors continue as he ages, they lead to much more serious actions by him.
In order to do anything he needs a stable environment in which to thrive and she should give u the medical card. It shouldn’t be an issue. But I believe if he is bound fed back and forth, it will just get worse. A doctor may be able to help
Sounds like y’all need family counseling !!!
Is he on medication? Participation in a behavioral program may also help. His physician may be able to make recommendations and referrals. An IEP, through the school district may also be an option. His last teacher may also have suggestions if you are able to contact them.
Nutritional supplements do help ADHD people I found out by reading Dr Harold Levinson’s books
Sounds like he needs medication.
I have ADHD and am able to have some control as an adult but as a child you literally have no control over the problems it causes because you haven’t learned how to deal with it yet. Medication and counseling to help him understand and control his impulses sounds like the best course of action.
It sounds very much like he’s being neglected at his “primary” residence, and therefore I’d probably look into how to get custody of him as that kind of environment wouldn’t be a help to him; he needs lots of structure and routine.
I don’t know where you live, but where I live we have government mental health facilities and bringing in an ADHD child whose being neglected would warrant a call to Child Protection, which would make the government actually have to investigate where they have previously failed to do so.
As for the other children, depending on their ages, try to sit them down and discuss with them what ADHD is and how it effects the brain and how a person acts. You will have to educate yourself on the facts beforehand because ADHD isn’t black and white, it can be very hard to diagnose as most symptoms don’t present as “symptoms”, just behavioral issues.
I don’t have advise for him being physical with his siblings as I’ve never experienced that, but I believe that with some medication and counseling that would stop after the chemicals in his brain regulated.
When my step kids first came into my life, it was rough to say the least. Their mom is very hands off and allows behaviors I would never condone in my house. Needless to say, my strict clean up after yourself earned me the title “worst stepmother that ever lived”. It stung but I stuck with it because I had a little girl too and I wasn’t going to allow misbehavior. The youngest has the same issues you described. Granted she started medicating him, I found that keeping him busy worked. I give him kitchen responsibilities with me (baking works best) or give him other responsibilities. It has worked well for us. It’s very hard for a child to consistently behave as expected when they have one foot in a different reality. Even now (7 years later) it’s still difficult for the oldest girl to know how to act at our house. She cusses and acts out at her mom. At my house, that doesn’t fly so she has to adjust accordingly. I love them and now I’m the best step mom ever but the challenges will always remain as long as their mom doesn’t parent better for lack of a better word. You just have to find what works. If he’s neglected at his primary residence, he may be acting out of anger. I don’t know you and I’m not making assumptions but if you’re here, you want to be the best you can be for him and your family. So hang in there. You’ll figure it out. Just constantly remind yourself that nothing you do can be permanent because it unravels each time he leaves. You have to reinforce your rules and perhaps start a good behavior chart. For any activities or chores done, I used to give a sticker. If they got a certain amount of stickers, they got a prize. They still talk about how fun that was. It helped them feel like their choice in behavior mattered. It also created opportunities for them to be responsible for something even as simple as organizing shoes. So you’ll find your niche. Hang in there momma 
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Alot of the time a different diet will help lower symptoms. Little to no sugars, no red dies that kinda stuff
My 9 yr old has ADHD too but this sounds like he could use some counseling to manage his emotions, he sounds like a kid suffering from depression honestly and it’s the only way he knows how or gets attention. See about getting him into a child psychologist. The violent tendencies are dangerous and can lead to worse behaviour if he doesn’t learn how to manage or coping strategies for his feelings. A parent at YOUR house (since that’s when he acts up) needs to go with him to these sessions - they will teach you how to help him cope as well. A few things I can suggest from my own experience are telling him things like it’s OK to be angry. It’s not ok to hit your brother or break toys. It’s OK to be hungry. It’s not ok to steal snacks and lie about it. Most importantly make sure he knows that it’s OK to ask you and his dad if there is anything he wants or needs - like a snack if he’s hungry or a hug if he’s having trouble calming himself down. Music and lava lamps also helped my son, he can stare at the lamp and count the bubbles till he calms down.
Also look into getting custody.
Well first off, if she is in the childs life as you are shes not a “single” mom shes a coparent. Obviously the child isnt disciplined when hes at home. So try standing em in a corner for a bit when he starts acting like a dink. If that doesnt help maybe he needs somebody to talk to since his real mom seems to be a twat and not give a shit about him.
Therapy. Please. I was this kid and all I needed was consistency and love when there was genuinely none. I was never receptive to 1 on 1 because I was resentful. That’s a bandaid. Show you care by not yelling or getting mad or forcing them to admit when they “stole” food. You can’t just use 1 on 1 and then still say, “I’ve had enough with him; I have my own kids to worry about.” That’s isolating to them and kids pick up on these things. They know how you feel about them and it only causes more resentment for the both of you. Get this kid into therapy for both of your sanity. I do not have a relationship with my step mom or father due to how my step mom responded to my childhood issues.
I think talk therapy for adults and play therapy for the child.
Have therapist consider if this is adjustment disorder /oppositional defiant disorder vs just a temporary cry for attention because he doesn’t have care nor boundaries at mom’s.
I’m not a counselor, so this is a general, layperson outline : ODD and ADHD often co-occur. ODD is also a spectrum that starts with problems adapting to change and high need to control. If this behavior persists for 6mo, it can be called Adjustment Disorder. If it continues to worsen, it escalates to Oppositional Defiant Disorder. If it is still not treated nor addressed it can escalate to Conduct Disorder 
. It’s much easier better to correct at the earlier stages. Give advance notice for changes in activities (including when changing from one one fun activity to the next type). Be firm and consistent with enforcing rules and healthy boundaries. ODD spectrum love to argue. They défine winning arguments as: causing a 5-minute delay in whatever you want to have happen next. Abort the argument.
I think counseling is the best option for him. Sounds like he’s got a lot of built up rage directed at you and his siblings, and no outlet for it. Make sure he knows the rules of the house every time he comes over and reiterate the rules. And make sure you’re getting help too, even if it’s self care. Can’t pour from an empty glass.
Agree with others on therapy. In the meantime: If he isn’t getting consistent care at his other home snack hoarding behaviour may be coming from a lack of proper meals and snacks when he is away from your house. While routine is very helpful, neglected children can often lash out against it at first because they are used to having to care for themselves and don’t want to relinquish control to the adult. So hiding snacks could be a control issue as well.
Does he have his own space to retreat to? His own things that others don’t get to touch? It can be very isolating to come into a “perfect” family and it can make you feel like a black sheep. Making time for him is great, but often people forget that kids also need their own safe space that is uniquely theirs. This will help him feel like he is a member of the family, not just a visitor.
From the sounds of it he has oppositional defiance disorder along with reactive detachment disorder and needs therapy the hoarding food is most likely because he isn’t getting enough at home and he is taking the way he feels out on the other kids which means they are most likely doing it to him at home as well I recommend therapy my son use to do this
Counseling and the such are all great ideas however I always recommend looking also for more physical root causes, particularly with diet. Visit a functional medicine doctor for a complete nutient work up, including food sensitivities/allergies, deficiencies, etc. Start to introduce more whole foods and reduce procesed/packaged foods. It’s really tough but our food choices really do impact brain health and development.
Find a good therapist who will
Help him express his emotions in an appropriate way. Have Dad contact the school child study team. If he doesn’t have an IEP or 504 plan have them start the process. They can help you with resources for a behavior therapist or other services he may me entitled to. About all remember the children that are hardest to love are the ones that need it the most.
I would looking into counseling for the entire family. There is a lot going on here and a trained therapist can have some useful feedback.
I have 2 boys that have adhd and it is treated and when they have their medicine it’s amazing to see the change. For a long time my husband and I were anti meds but we knew we had to something to help them in school. My oldest son who is now 15 started in 3 rd grade and went up 3 reading levels that yr. please feel free to pm me if you have questions
Not to diagnose, but I have a friend with a child who has very similar tendencies. He was diagnosed with RAD (Reactive attachment disorder). I definitely encourage therapy as that is what has helped him the most and where he may be able to get a diagnosis— whatever that may be. Best of luck.
He needs a good therapist and specialist if he had medical with mom it counts even when with you and dad he needs consistency and some discipline
Yes it plainly to see he needs helped, therapy and a lots of support from you both ,And counseling for you would help a great deal, because it would help you in making right decisions on any situation thats you may come across, may God give you the strength to be their as a family and making the right choice 
you are doing great but needs help for sure so that it does affect your marriage.
Make your husband responsible for his sons behavior. How do your husband care for him and stay with him most of the time. Have him play games with your stepson and other children. If he is abusing your children, he needs to be separated and cared for And treated the best way for his condition. Good luck.
Look up Genexa products. I can not say enough great things about it! It has helped my grandson who has adhd as well to be & feel more calm. It changed his life especially at school to be able to focus & be settled down enough to learn & do great in school. Good luck & keep your faith all children grow up eventually. It’s really great you care & are there for him.
Im wondering why the father hasn’t pulled him out of there , if he’s not being treated right. I had a mother that didn’t care and a father that abused me later down the road ( not saying your husband is abusive) buts it’s clear the boy is suffering under his mother. You might want to consider a psychiatrist.
Sounds like you need a good psychiatrist to get his meds in order and possibly further evaluation. He’s not giving you or his siblings a hard time- HE is having a hard time. It sounds like he may also be getting way over stimulated and possibly has binge eating issues, both can go hand in hand with ADHD.
It sounds a lot like he’s scared of getting in trouble: hiding broken toys/snacks. It also sounds like he feels like he isn’t getting enough attention: wishing the others weren’t born, hiding toys that aren’t his. Therapy definitely will help. He needs to know he can and should be 100% honest and that honesty will help everyone involved get a win-wim
Quit calling him your stepson he feels you’re dislike for him and for his mother. He needs your touch hugs and kisses approval that is sincere you are the adult Treat him like you want to be treated it’s not hard
As a person with ADHD who was passed around the family. Get him therapy. This sounds like he is acting up because he has unresolved issues to deal with emotionally. Also, if he’s primarily at your residence and also isn’t taken care of at their home then you need to go to court and file for custody.
Don’t hear you saying anything about his Dad or your husband. Sounds to me like he needs to step in and be proactive. You need to have a long conversation with your husband. Then, get your step-son to a doctor for help
Kid need consistency. He need praised when he does something good and a little ass whooping when he does things he knows damn good a well he shouldn’t do.
Document all these incidents dates that you have had him conditions that he was in when you picked him up or when he arrived photo of his hands clothes , hair etc. and the incidents with your children . Social Services may require that you don’t subject your children to this behavior and insist that he be kept away from your children since they should be protected from this disruptive personality. He needs his father to step up and protect him from the neglect and abuse he is receiving from his biological mother.
You lost me at he stinks? Long nails? Obviously he needs a little more love then that’s being offered… he is only 9 give him a break! You stated he has mental and behavioral issues he already has odds against him… is he on medication? I would recommend Extracurricular activities along with medication and patients… and if you believe the mother is “unfit” you should know exactly what to do!! 
STATE
You need, at the least, mediation. Get a family law attorney. Keep a journal of happenings, videotape his behavior, keep toys he has broken, bruises on your son’s body, his long dirty nails etc. He needs more than you can provide without professional help. The bio mother is committing fraud if she takes money from the government meant for his needs and you are also paying for his care. I feel very sorry for him, but imagine the trauma your children are experiencing.
Rearrange custody, that child is being neglected. It might be hard at first, but he is NINE. He isn’t acting maliciously, he needs an adult.
This is clearly his need of attention. Even if you do the right thing when he will return to his mother it will start all over again. He needs a constant family. 
I think instead of doing you and him do include him in stuff with his siblings and stop thinking of him as a step. If your child were doing these things what would you do. Then do it.
Can you imagine being him? Look at all he’s going through… having adhd isn’t easy for him either. Being passed around never feeling like he belongs. I understand the frustration but he needs stability and constant consistent love and nurturing. He needs to feel secure in his home life no matter where he’s staying. He’s only 9 years old, he’s still a baby. If you don’t get it under control now, things are going to get way worse right quick. Do your research on adhd if you haven’t yet. Get him the help he needs and get him out of his mothers care if at all possible. There’s help out there but you have to do the work to make it happen. It won’t be easy but it’ll be worth it. If you really love him like he’s your own then it won’t be that hard to figure out. We as mothers have that fight in us for our babies. Hug him every chance you get and tell him how loved he is and how important he is.
He is either hurting or has a medical condition which needs to be addressed immediately,if he is causing beatings and bruising to younger siblings,something is seriously wrong,start with the doctors and keep pushing,the other kids get very badly hurt or worse,not trying to scare you, but being very realistic
Specialized therapy and family therapy…. Stick with it for 50 weekly sessions then once you feel like you all have the tools needed… maybe monthly or quarterly check ins.
He needs to be on medication and go to therapy. Your husband needs to file for custody so that this child has a loving stable home.
He needs consistency and clarity about how things are different between his environmrnts. Children crave stability and clear limits, they just don’t know they want it. He’s confused and conflicted because his footing is unsure EVERYWHERE. He doesn’t trust how someone is going to be or what hes going to get from people or situations so he desparately grasps for control however he can get it. It’s an ugly kind of acting out that needs firm, unwaviring, loving boundaries that allow him to see and feel the tangible proof that the adults at your house have him securely grounded. Natural, unemotional consequences or gushing rewards. Unconditional love despite mistakes. Emote loving approval and excitement or sad disppointment. Hes seen too much dismissal, anger, spite, berating or bribery in other environments. He’ll come to know where he’s most secure. Therapy would be great, if you can make it happen.
This poor child is feeling unwanted unloved and doesn’t have natural mom and natural dad together. He’s split between two households and on top of that the household with natural mom he’s tossed around and unloved his brain is still growing he’s a child his father should be more of a father and take action to show he CARES it has to start with him because you don’t seem vested you’re venting about yourself and you’re one of the grown ups if you aren’t willing to support your husband to be a father to his child when you have two children by this same man prep for karma on the off chance the next hot young thing turns your husbands head leaving your home divided I do t wish that on anyone just know when humble pie is on the menu it’s unsettling when served - you signed up to marry a man for better or worst you knew he came with a child and you knew that child’s circumstance - being a parent requires patience nourishment love and understanding on top of that compassion I get it becomes overwhelming at times I get sometimes you need a break I also get that you’re an adult the other mother in the situation and if you felt comfortable enough to post on the Internet feeling like a babysitter and mentioning not getting financial help to parent a child your husband helped create you may need to pause and prioritize this child and what the child is enduring and then maybe see someone to work through your feelings so you can be a better support system to this child and if you’re unable to or have no desire to or when you look at this child you see as gross - don’t stop your husband this child’s world is fragile and uneasy and having a disorder doesn’t make it any easier - seeing siblings who are in a better situation than him doesn’t make it easier he probably feels unwanted in both places. Prayers for this child and everyone involved
This child needs to see a physician who specializes in ADD, You could limit the time you have him until mother takes him to a physician or offer to take him yourself.
Is he on meds for ADHD?! Maybe he needs to be. When my son was 10 his pediatrician wanted to put him on meds for his ADHD I was against medicating my son. But I regret that decision he suffered all through grade school. Now as an adult he is finally on meds.
It seems like hes not getting fed at his moms house and it also sounds like he gets away with alot
My son has adhd and asd and auto processing disorder he does this I have him primary and when he goes to his dads gets fast food toys money what ever he wants. When he is hear after being with his dad he becomes a different child lying stealing breaking things hurting his lil sister similar things. I learnt one on one with him lots of patients. When asking him to do something its in one or two steps. I also get him to do chores to get extra treats that he can pick on shop day. I am on a disability pension and struggle financially but I try to do my best. Maybe sitting him down ask him why he is acting out, tell him you love him no matter what. When he does something bad make him sit on his bed in time out so he can think about what he has done and also gives u time to stay calm. When the time is up ask him to apologise and ask him why he was acting out. Always give a hug and tell him you love him. (I no its hard when they do really bad things to ur children but think of this he is a very confused hurt little boy who needs ur help and love) get him counselling. If he is taking food is he doing it when he first comes to ur house and before he leaves they may be an issue with him not eating enough. I would also give him permission to have snack so he is not taking too many now at first he will push ur limits with taking lots but give it time and it will slow down. You could also during this time not have as many in the normal place maybe keep some in ur room or somewhere else. I would also take him to the park or something he is interested in. You can use this as a reward for good behaviour make a chart with him and engage him to write what is a good choice and a bad choice. I hope this helps please feel free to pm me if you want to chat more my son also is only child at his dads and has a baby half sister here at mine they are 4 n half yes diff in age
He has adhd, this is normal behaviour, my 8 year old boy is exactly the same…
Tell your husband to step up and deal with HIS SON and also you might take Mom to court about the lack of time she spends with the child and what you have to pay for while he is at your house.
Went through this for 17 years. We never came up with a solution. This is an impossible situation, and we ended up just living through it.
I would fight for custody of him. He will know he is really wanted, and then maybe you will get the assistance you need. Since you have him most of the time anyway at least you’ll have more control.
My son has ADHD. After his dad and I split up, his behavioral issues got out of control. If your son has state insurance, talk with his school or pediatrician and suggest he might need therapy. My sons insurance covers for him to have in home and at school therapy sessions and it has helped my son tremendously. His pediatrician also said she felt he needed medication to help with his symptoms and while I didn’t necessarily want my child to start taking medicine for it, it has made a world of difference. He cooperates so much more with therapy and he just seems to feel better as well. His therapist told me with ADHD the world is always overwhelming because you’re paying attention to everything around you at all times and it’s almost impossible to stay focused on just one thing. Because of that a lot of kids have anger issues since they don’t know how to deal with being so over stimulated at all times. My sons therapist asks him what causes him to get angry and talks with him about it and then they talk about different ways to help deal with the anger that isn’t violent. Your son’s mental health is very important and a reason he might be acting out is because he feels like he doesn’t get enough attention. If mom is never around and then dad also has other kids that get attention as well he probably feels like no one truly cares for him. As adults, you know that isn’t true, but unfortunately our minds aren’t always kind to us and he might feel left out at both homes. Maybe try planning some one on one time with dad or you so he can feel special and that his feelings do matter. While out ask him if anything is bothering him and let him know you want to listen and that you care. It’s can make all the difference when a child knows their feelings and thoughts matter and that someone will listen to them. I wish you the best, I understand how stressful it can be
Get social services involved you should not have to put up with this and even kill one of your children although you treat him like your own he needs a stable home and she has all the money, only thing to do is social services as his mother really has nothing to do with him and his ADHD could get worse with-out proper treatment but that is not your job his father can do it
Hubby needs to get proactive…it sounds like he’s leaving most of the problem up to you. He should have him evaluated by a shrink and file for primary custody. He will need ongoing therapy, meds and a stable consistent environment. (Been there, done that.)
Document! Document, document. If he is coming unbathed and firty, this is neglect. Take pictures.
Could it be the fact he goes home to that situation and comes back too your family and can see thats the living situation is alot more of what he is looking for inside and tends to be a bit jealous of it? The food part could be that he is having a growth spurt/ reaching puberty as that is what my son went through when he was pinching extra food i just made sure to give him that extra more at dinner time and some thing little before bed like fruit or crackes… the one thing they need the most is too know they are loved and have that time to get one on one attention separately from yourself and the father make a chart so its something he can look forward too while at your home it doesn’t take long for them too make a mistake but thats all it is as long as you address the situation for him too understand he will eventually be able to remind himself in time. Dose he have his own space too look forward too when at yours? Thats also something I found that my son in similar situation liked eg. His own room with his own things? Could help with him breaking other siblings toys…also if you see yourself as his mother don’t refer yourself as a babysitter as that allows that distance to be there he needs a mum and father and honestly from the things your said it sounds as tho he likes it more at your house he just doesn’t know where he fits in, have you perhaps sat down with him at all too talk about how he feels emotionally, what goes through his mind when he dose certain things? Allowing him to open up too you will help him know who too turn too when he needs to… also find some hobbies for him too do that keeps his hands busy with children that have adhd I find my son enjoys Lego’s alot it allows him to learn concentration & creativity, gardening for patience and art for calming and then some boarding or other exercises to burn that energy thats built up inside of him, all these activities have helped him in so many ways, so I hope this can help you be strong the child is probably just looking for love and stability. 
Try eliminating food with red dye in it.
He needs attention. And a lot of it. Try doing some activities with just him
Turn the problem over to your hubby tell him if he can’t control him he can’t come over to our house because he abuses his other children
Research ADHD and supports available in your area. The important thing to remember is that their behaviour is not due to poor parenting, and while they may “know better” their brain is unable to put the brakes on. Think of it this way, he has the brain of a Ferrari with the brakes of a bicycle. Often times medication can be of help as well.
There are many strategies that can be used to support him. Far too many to list here but tons of reading available online. One thing though that is key, is consistency. ALL parents should be consistent with parenting styles.
Hopefully hes getting psychiatric help. He sounds like hes a very frustrated child and resentful child.
He’s used to being the youngest and getting extra attention. Try to do some things with just him.
Sounds like he needs child counseling asap
He has a lot more going on than adhd
So unfortunately youre fighting another parent that clearly doesnt want to be a parent. I would really start to set boundaries and consequences for his behavior at your house. While its not the childs fault they need to learn right from wrong…and counseling may be good because the lack of consistency and probably lack of attention from his mother is weighing on the poor kid.
As I see it, you’ve got 2 choices…
Invest in him with a positive and supportive attitude and understand he’s screaming for help that he’s not getting with mom.
You and dad need to be side by side and uniform in everything he is involved in whether it’s discussing with him the consequences for his improper behavior or rewarding him for improvements.
Kids generally only respond to consistency of the results they know they can depend on NOT changing.
Remember His life situation is not his fault. I agree and feel the same as others have mentioned… you need to get him out of the mom’s home as much as possible to show him a better example of how home life is suppose to be.
Or
Become like mom has become and be another reason he’s going to be someone else’s life problem… and he’ll most likely become an abusive adult and eventually an abusive parent.
Sounds like dad might also need to get a lot more involved in this situation.
That kid needs some serious help. If my husband’s child was laying hands on mine, they’d soon be changes because I’d be gone.
you should put down the time you have him and report it and go for custody
This is between your husband & your ex, unfortunately- YOU have NO power in this situation- only what your husband is willing to enforce- & it sounds as tho’ he’s unwilling to address the real issue- which is the custody agreement. Having been there- MY solution was to start telling the brutal truth to the kid- “You’re Mom is a big fat liar”, etc. because the problem is the kids PARENTS_ not the kid ~
Sounds like he is seriously acting out due to the entire situation he has been exposed to. He needs therapy ASAP. Be best if you and your husband could be present for some of his sessions. The doctor may also try some medications that could help him. But that would definitely be my last choice after all other attempts fail.
Sounds like dad needs full custody so he can get the attention and care he deserves.
Son and father needs therapy.
Get custody of this confused, neglected child and get him some good therapy.
I knew a kid like this that turned out well. Why? Because his mother’s house was full of Jesus. And as he grew he states he always felt that presence… changed him. And trust me he was one of those potential animal killer type.
He needs a good whopping. Maybe he needs a lot more than one
the benefits travel with the kid if they are for the kid just report her
You don’t it’s not your kid
Renee Garcia-Fletcher
He might be autistic
Try counseling for him
Why do people post their problems on social media when there’s clearly a thing called THERAPY🙄
Love how you started this by saying I’m a mum of 3 . I’ve got no advice but I liked that . Good luck xx
Im guessing he gets treated this way at home, being the youngest there; then he acts it out, to his advantage, when he’s the oldest with you. Im not sure how you could handle this but I’d beat his butt. He has to know he cant get away with it in your home (your rules) and put the fear of God on him. I def would never want to live in that daily situation. You have other kids to think about. I was a foster parent and those kids corrupted my kids from day one. I feel your frustration because we werent allowed to spank fosters so my kids lived with 2 different standards.