Okay, so here's the deal: I went out to breakfast with one of my friends and my cousin/BM the other day. While we were eating breakfast, my BM nonchalantly brings up that she hung out with my ex fiancée the night before. My friend and I looked at each other in disbelief, while she went on about how they only talked about Pokemon and played Pokemongo together. I acted like it didn't bother me, but it really does and I feel like I need to make if known that it makes me feel very uncomfortable.
A little backstory on my ex: He was very mentally abusive and would occasionally become physically abusive after heavy drinking. I was with him on and off for 8 years and everyone hated him, including this cousin that I'm talking about. So why now, after we've broken up, and she's even ASKED to be in my bridal party (I obviously said yes to her) in my wedding with my new fiancée, is she hanging out with him and being friendly?
Cont'd in comments.