Is my friendship over?

Sorry for the wall of (con)text. A few years ago, I (25f) went to an overnight house party/campout with my best friend (27f) and her boyfriend (40m). We had been drinking heavily, and when I went to set up my own tent my best friend strongly insisted I just stay in theirs. She had me sleep between her and her boyfriend. I asked if she wanted to switch places, and she said no. So I'm trying to sleep when he reaches over and grabs my butt. There is no way he mistook me for her, so I swatted his hand away, hoping he got the message. He did it again, and I swatted his hand away again. When he did it a third time, I got up and left the tent. I spent fifteen minutes huddling next to the bonfire with the few people still up, and eventually fell asleep on the host's couch. I felt sick to my stomach for a week after. I felt guilty, and I didn't know why. I was angry and anxious because I realized that all the times in the past few months her boyfriend had groped me, and I thought it had been an accident, hadn't been accidents at all(I had been just hoping that he really had managed to trip and land his hands on my breasts. It sounds so dumb now). When I told my friend about what happened, she wasn't surprised. She said she saw the whole thing but didn't say anything at the time. Apparently he had followed me out of the tent? I hadn't seen him at all when I was at the bonfire, and I told her so. She said she thought he wanted to try for a threesome to make her happy, so it wasn't his fault, even though she also insisted she never asked for a threesome. What the heck? This only made me think that she had wanted a threesome and instead of talking to me, had her boyfriend grope me, and now was backtracking to save the friendship. I felt sick. I hadn't even considered this might have been planned by her before she brought it up. However, I didn't want to base my actions on assumptions (even if they were grounded on things she hinted at) because she had been an amazing best friend up until this point, and I kept in mind that she is also an emotionally fragile person. So I told her I didn't want to get between her and her boyfriend, and I would support her decision to stay with him, but I wasn't comfortable around him anymore. I thought she would respect that. In the years that followed, she would drag him around everywhere without asking. I was scared to say anything because she has BPD and tends to spiral emotionally. Eventually I got mad when I realized she didn't think what happened was a big deal at all, when in a different conversation, she said consent wasn't black and white, it was shades of grey. I had told her how upset I was about what happened and I realized she had seen the whole thing as "shades of grey". We got into a fight and I told her I didn't want to be around him anymore, and not to invite me out if he's going to be there. But she hasn't tried to spend time with me since, and the only times I hear from her are... yep. To invite me out to his friend's parties. I brought it up and she said she wasn't thinking about what I said when she invited me to his events, and not to take it personally. I feel like an a**hole because I told this story to a mutual friend who is also a coworker of hers, and I know it reflects badly on her but I was fed up with her pretending her boyfriend isn't disgusting. I would want to know if someone I knew had a history of touching people inappropriately too. I guess I am also realizing that I need to mourn the best friend I had for the past ten years, and start to move on. I am extremely hurt, and she hasn't reached out at all, and I feel like I told our mutual friend was more out of anger than anything, and I am not proud of lashing out. Even if people do deserve to know that he has a history of preying on drunk girls (I wasn't the only one something like this happened to). My friend got me through some incredibly dark times, and I don't want to say goodbye to our friendship. I wish I knew how to fix things.

As an outsider looking in this is what I see: your friend INSISTED you sleep between her and her bf, and him grabbing you wasn't an accident on his part, or even ALL his idea. She set you up. You didn't want to be part of a threesome, so you refused. The other possibility is that he has her sooooo bamboozled/intimidated/whatever, that HE'S only willing to continue a relationship with her so long as she keeps trying to set up threesomes with her friends. You talk about her inviting you to his events. Have you suggested a girls' night out, just the two of you, or with a couple other girlfriends? A quilt show, a craft fair, a Christmas concert, something the bf would not be interested in? Unloading on someone she knew wasn't the most discreet thing to do, but I'm guessing, (since it hasn't gotten back to her or anything) you unloaded on someone who took this on and was wise enough not to repeat it. (I'll bet you had a gut instinct this was a safe option) Go ahead and mourn this relationship. It's sad, but it sounds like her moral code and yours no longer coincide.