Would this make you mad?

So I'm not sure who all is familiar with SnapChat.. Basically it is an app that you can record videos and pictures with and upload it for all your friends to see. Well, I went to dinner with one of my friends tonight. We were best friends in high school, only close friends now, but close enough for me to be one of her bridesmaids. She was talking about people she hated and named off three people. She asked me if I hated anyone and I said "I can only think of one, and that's my ex." She knows who my ex is, and she and her boyfriend used to be friends with him. They both know my ex cheated on me and never apologized for it as well as make up lies and stories about me. My ex even used to talk bad about this friend of mine while we dated and I always stuck up for her and her boyfriend. She and her boyfriend then started talking bad about him to me, saying he was crazy, a liar, blahblah.  I get home, get on snapchat, and she and her boyfriend are all of a sudden hanging out with him! Playing beer pong with him. My FRIEND (not her boyfriend but HER) was recording videos of just herself and my ex laughing together and making videos together. She KNOWS I follow her on this app, she KNOWS he cheated on me and broke my heart, she knows I was just talking about him to her at dinner! I can't wrap my mind around why she thinks this is okay. Am I overreacting of would this make you angry too?