Gf Cuckold

My girlfriend and I have been together for almost 5 years now. About a year into the relationship we decided to try something new. She thought my friend was hot so we were going to have a 3some but it turned into just her and him. Since that day she has slept with 18 other guys. 7 of them creampie her. She talks about fucking other guys all the time and doesn’t let me fuck her anymore because I’m not good enough. She is supposed to have sex with a guy tonight that she met at a bar last weekend.