How do I (30F) explain why I stopped talking to ex-bff (31F)?

r/

Throwaway for obvious reasons.

tl;dr: stopped talking to ex-bff coz she was hitting on my bf. how to explain it to mutual friends years later and not get left out of friend groups

I (30F) stopped talking to ex-bff B (31F) six years ago. Long story short, I found out she was trying to come in between my bf (30M) and I. A lot of small manipulative stuff over time, for example she started organizing stuff with the friend group when I wouldn’t be able to make it and she posted photos and videos of her with my bf dancing to some tiktok trend (no touching) in an extremely low cut blue dress – she had asked me couple of days earlier in a teasing way what color lingerie he likes and I’d said blue as a joke (childish and yikes, ik).
The reason I didn’t go to that particular party was coz I had just found out my dad was not going to make it from stage 4 c**** and I was at my sibling’s. She knew this. In fact, she was the only one in the whole group who how serious everything was at home as I was closest to her, my bf only kind of knew but we had just started dating then. I didn’t confront her coz I didn’t have the energy for it and blamed my bf for hanging out with her and fought with him about it coz back then in my mind it’s on the guy to set boundaries. I saw only the video she posted with him and her and assumed only they were dancing together. He told me she had danced with all the guys there, he had refused at first when everyone was calling him to join and joined only when everyone insisted.

I also know that she had flirted with all the guys in the friend group. But when they asked her out, she would say no and then boast about it to the girls in the group. My bf was the only one who didn’t reciprocate and instead told her he liked me to which she had offered to ‘help him’ get close to me. He said no to that and had directly asked me out.

Anyway, I lost my dad a couple of weeks after that party and I stopped talking to her during that time. My bf wasn’t really friends with her as he met her through me so he doesn’t talk to her either. It was easy to cut contact as we moved cities together for new jobs.

I avoided her as much as possible except for ‘surprise’ visits from her when I was meeting others in the friend group in my city. B is very charismatic and outgoing and I was the only girl she did this to in the group. B also pretends she doesn’t know why I stopped talking to her – and everything she did was in ‘plausible deniability’, nothing really happened so I look like I’m making a big deal out of nothing even if I did confront her. It felt like whatever she did was to get under my skin.

B is the ‘fun one’ in the group so when I stopped talking to her I automatically got left out of meetups etc which hurt. I learned the hard way that most people pick the person who is convenient and fun to be friends with and I’m no longer part of that friend group.

I recently met a mutual friend C (who is outside of this friend group, I met her at a totally random place) but knows B through work and she kept saying B was saying they should catch up bla bla bla. I told her I don’t really talk to B anymore and C kept asking why. I said we just grew apart coz I didn’t want to badmouth her as she married someone else now and I don’t want to dredge up the past. I want to move on but clearly I still have issues over the petty trauma she caused during the hardest time of my life. What do I say if people ask me? I still feel really bad I got left out of that friend group when I stopped talking to her and B seems to know everyone and it feels impossible to make new friends who don’t know her.