My best friend is dating my bully?

My absolute best friend is now going out with the guy that made my 3rd period last year a living hell because I'm gay. And now she's dating him. I'm pretty sure I told her about him. But I don't know if she remembers. Plus he is a complete player, with a new girlfriend every other day. What should I do? I wanna be mad at her but I want her to be happy but I really am mad her for that.