Single mom to be with a potential dangerous baby dady, advice?

I’m currently 21 weeks pregnant with my first child. His biological father, along with being mentally and emotionally abusive, cheated on me with my best friend for over a month. during that time told me that he was afraid he would become his father, who molested a child. The baby daddy was sexually assaulted throughout his childhood and did the same to his sister. After finding out about the affair my former best friend and I got into a physical altercation and she was arrested and has a no contact order for my protection. he is still living with her and I refuse to have my newborn around her because I’m scared of her hurting my child which he says isn’t my choice. I moved back to my parents house because the three of us were living together. he says that his future is with her and I have to be okay with her in the child’s life. After talking about it for some time The biological father agreed to sign his rights away under the condition that I would have a forced meeting when my son turns 12. I don’t agree with it and I don’t want him in my life or my sons life whatsoever. Not because of the cheating but because he couldn’t tell me that he wouldn’t abuse my son and refuses supervised visits. We arnt married and had only been dating a short amount of time. I’m not really sure what to do or steps I should take to make sure that my son is safe from him after he is born and when he is older. Has anyone else gone through something like this? Or if you know what I should do please leave a comment. I feel so alone in this and just need some advice. 😔