If it was just a prank, meant for laughs, without any ill-intentions (as it seems to me) I don't understand why she's mad either. I've done that very thing to siblings and would do it again to them or bf. None of them got mad at me btw...

I'm confused by her anger, unless the other posters are right and you were just being an a.s.s, although... that makes no sense either because you seem as confused by her reaction as I am.

If you were being mean deliberately, you would have been expecting her reaction no?

I'm confused, I wouldn't have gotten angry, nor would I label fooling around abuse. When you apologize, please ask gf what about your prank was hurtful or angry-making, because I'd really like to understand