Help me out~~Will award points?

She told me she was going to hangout with her friend, Tess on Thursday, but Tess mentioned to me that they didn't. When I asked her about it she initially tried to cover it up, but then she admitted that she hung out with another guy friend. She isn't cheating, she just knows I REALLY hate him and didn't want to upset me. After I confronted her on it maturely she tried to turn it around on me and act like it was my fault, because I would have been upset if I knew she was with him. She apologized very sarcastically and insincerely and hasn't talk to me since yesterday. What should I do about this?