Ending a 7+ year friendship

My bestfriend and I have been friends for many years. I ended up moving out of state to marry my now husband. We remained friends even after I moved. She met someone from work who is a horrible person, before I moved he expressed interest in having a threesome with us ( not something we would ever be cool with) to me and when i told my friend she was in denial and said he was probably joking but it wasnt the first time he came on to me. Next, I catch him on his phone watching porn while my friend is making him dinner. He would always talk about his favorite types of girls etc ( totally different than my friend - really disrespectful) i hated him from day one and tried hard to show and tell her he is not a good man. My intuition was ringing alarm bells. I move out of state any way and despite my hatred for her then bf, she gets engaged and i support her as a friend even though i think her fiance is a shitcase. ( he already had 3 babymamas and was a druggie) he cant marry her anyway unless he has his first marriage annulled from a woman he married fresh out of highschool. He told me he hates marriage and will never marry her in a covo with a few friends. I told her and she said he will change his mind. One of his daughters or kids from one of his three baby mama accuses him of sexual assault or something bad enough for him to be looking at 20+ years in prison and be on the sex offender registry. He accepted a plea deal. She is still with him. I dont feel like i can keep the friendship with her anymore.