I think that you should just go, for your girlfriend's sake. Are you planning on skipping every get-together that her cousin could possibly be at? I'm telling you from experiance-- she won't tolerate that forever. And from the way she's acting, it sounds like she doesn't want to deal with it now. Why don't you just suck it up and go, and don't give her cousin the time of day. If she tries to start stuff with you, she'll be the one looking like an ass. She'll probably be so busy entertaining her other guests that she won't even bother with you. But you should probably try to end all of this will her asap, to avoid future problems. Can't your girlfriend sit down with her cousin and ask her what she has against you? I know she had a problem with her also, but they are cousins, and should try to work it out. It also sounds like you and your girlfriend have some issues to work out too. You didn't include too much info about that, but it sounds like it. So why don't you call her (not text her) and talk to her about what's going on. It's silly to play games, and that's what it sounds like the two of you are doing