no relationship, no crime, but if she really liked you, she would have got drunk and screwed you. it sounds like you really weren't on her mind at all. fooling around might not mean anything to her, she could do it just for fun.

sex with random people is dangerous and do you really want to be with a girl that does that? that's how stds get spread, hope she used protection. this situation is really only your call. but i'd tell her to fuck off...