Do I sound bitter?

So my ex husband and I have been split for years now. My ex husband finally stop sending me gross text messages, d pics and asking for “his family back”. Mainly when he’s drunk off his ass. I have kept my kids for the most part, from him and his gf for multiplier reasons. DV, Alcohol, drinking and driving, DL revoked, arrests. She has one child which she has lied about being his and he found out. They are very on and off. She doesn’t like me simply for that fact that he still has feelings for me and tells me that she’ll never be me. She doesn’t like me or my kids. I care about my childrens well being and safety. Now that my children are older. 10 year olds. They don’t want to talk to him. They said they want their step dads last name. I have never bad talked their biological after all these years. Never to them or in front of them. I wanted them to have their own mindsets. Is it wrong for me not to push them to have a relationship with their biological now? He doesn’t bother to come see them, or financially support them. His thinking is that now I have a husband, it’s his responsibility to take care of us. Even when I was jus dating my husband, he’s tried to say that I have two incomes now so it’s not fair to ask so much from him. So for about 4 years now, I haven’t bothered him for a dime or his time. When he messages me, it’s about how he what’s sex or whatever from me. And then when I tell him you can only message me when it’s about our kids. He gets ass hurt and I don’t hear from him again for weeks or months. Now all of a sudden, he wants to call them and take them and tries to plan out of the country trips. He asked me for their passports and such. This man doesn’t have a vehicle. Stable home. I don’t even know if he got his DL back. So I told him no. You can come see them for a bit by yourself until they get use to you. Is that a sensible request? And when he does call, I ask my children, and they say no. They don’t wanna talk. Do I sound like I’m being unreasonable with any of this? I swear I’m not trying to be bitter but it’s my kids I worry about. I divorced this man because one time was enough for me baby, I wasn’t about to go back for round 2, 3 Or 4. I didn’t want that for my children. Idk I’m jus looking for opinions from any side really. He’s called me bitter and that I’m being dumb and keeping him from his kids. So I’m jus wondering