My family member has become friends with another family member's abuser

TW:SA with a minor

My 48M uncle has become friends with my (43F) mom's abuser.

This all started when i got a call from my cousin a couple months ago. He called to tell me that my biological father has become friends with my uncle which is his (cousin's) dad. He knows that my biological dad and I do not have any relationship, we never had one. When I was born he was in jail. When he got out of jail my family had already moved my family and I to another state. He never sought out any type of relationship with me.

After years of wondering about who my biological dad was my mom finally sat me down and told me that their relationship was not what I thought it was. My BF (Bio Father) was in his 40's and my mom was in her teens when they met. She basically told me that he groomed her and there was SA involved. After that It completely changed the way I thought about my BF. After years of always wondering why he never searched for me and now this? I felt disgusted with myself because of who I came from. I changed my last name shortly after because I did in fact have my BF's last name.

I made peace with it until now. My family is putting together a party for my grandma and grandpa's 50th anniversary and we are supposed to host it at my uncle's house In the state where I am originally from. My cousin continues to tell me that my uncle wants to invite my BF to the party. I told him right away that I did not want him there, there is no reason for him to be there. We are celebrating my grandparents and I did not want to make this about something else. I also have a son so for the protection of me, my mom, and my son I asked my cousin to tell my uncle that I did not want him there. I thought that my uncle would have the common sense to know that he should not have him around us but that is not the case.

My mom told me that she was upset by all of it. She was upset that my uncle was not the one to tell her and more upset that he continues to be friends with him. So now we are not on speaking terms with my uncle, my uncle isn't on speaking terms with my mom and his other sister who lives in his state. I had to reach out to one of my half sisters that knows my BF more than me and she really concerned me. We are dealing with a lying, manipulative, narcissist type of man. I feel like my whole world is crumbling. Im losing my family to this abuser and they don't care.

I know what i need to do but It hurts me more than anything to give up on this relationship with my uncle. He was a father figure to me when I had none and has always loved me as if I were his own. He would do anything for me or so i thought. I can't forgive what he has done to me and my family. I have no Idea what to do or where to start. If anyone has gone through anything similar I would like some insight.