Definitely go to semi. Your girlfriend must have been looking forward to it for a long time, and from her point of view, it probably seems like you ski ALL THE TIME anyways. (as awesome as skiing is) so just make one exception for her, it would probably mean the world to her that you made this sacrifice. There will be other opportunities like this one, trust me. im experienced. just go to semi and make ur girlfriends day. otherwise you might lose her....