My friend lied about her birth control and I want to tell her bf

I have a friend that took out her iud and was trying to get pregnant “on accicent”. One day she told me that she felt like her boyfriend was never going to propose to her and she wanted to get pregnant because she felt that getting pregnant was the only way he would propose. She ended up getting pregnant and he still hasn’t proposed. He knew she had an iud in and thinks that it must have fallen out or he was too rough and it came out. Now they are financially struggling and she asked if I wanted to help and move in with them to rent the extra room they have which would of been the babies if they didn’t have to struggle. I declined and now shes upset because I don’t want to help her and her boyfriend. I told her I didn’t ask her to get pregnant and that it was her fault for trying to trick him on proposing which he still hasn’t done. She got upset and we havent spoken. Her boyfriend is now talking so much shit about Me and mutual friends come and tell me. I kinda want to go off and let him know what was up but I figured I let it go. They are stressed enough as it is. But that bit in me always wonders if I should spill the beans

Why is she even upset… she planned all of this & now that it’s happening it’s like it’s your fault since you won’t help. I hope you know you are not in the wrong here, let them talk their shit. Obviously your friends know something weird going on too since they tell you. I would probably tell him, there’s really no need too but her talking shit was unnecessary too. Tell him, at least you can know you tried.