Okay I have known this girl for a while. A year ago we were friends but not very close, she was closer with my bf at the time. Anyway, during the last three months of my ex-bf and my relationship, I was very suspicious of their friendship. I confronted him once, but he denied that he had any feelings for her. Anyway, this past holiday I found out that he did cheat on me twice with her. My problem is, a few months after my ex and I broke up, me and her became very good friends (actually best friends), and believe me there were so many occasions where she could've told me what happened between the two of them but she always denied it, until that night when my ex told me himself that it did happen and I confronted her. I was just angry because she always lied to me. But now when I think about it, I find it really hard to trust her, especially when it comes to guys. I really don't know what to do. I don't even know if I should be friends with her.