My bf is going to an ex-classmates party. He was in a relationship with one of his classmates for 5 years, she was the girlfriend before me. The friend (and ex-classmate) who organized this says that I can't go, because plus ones would make it weird. My bf will go, even though I expressed my concerns. He has done things like this before. He talks to her almost dailiy, even though nothing special, trying to keep it as short as possible, but she doesn't have any other friends according to him so he pities her and doesn't want to stop talking to her. This information only surfaced a day ago and I'm fucking heartbroken. Just tell me that he fucked me over so it sinks in.