I'm going to tell my girlfriend we would break up if she dropped out of school to travel around europe for a couple months with her friend
Why do you feel this way?
I am paying her tuition she doesn't need to whore around europe.
It is good to be honest how you feel with a partner. If you call her a whole she might dump you.
Why?
First off using names is hurtful, I get you are paying for her classes but you don't own her. You should talk with her about the trip, it might be that you and her can go instead or she could decide to finish school then use a vacation as a reward.