I have a problem with my gf heh can ya help me out?

Well you never know I guess. Maybe she just didnt find humor in something you said or something. But for whatever reason you just walking out and slamming the door is a little childish. Anyways if it is still bothering you. ask her. otherwise you really have no choice but to just get over it, because you will just be boiling over nothing if you cant even talk to her