Your walking to class when your rival suddenly snatches your binder out of your hands.

"Hey give that back!" You say as you try to get it from him. He starts flipping through your tests

"Ha, I knew you lied about getting 100 on this one!" He hands back your binder satisfied. "Wha-you can't just do that!" He leans against a locker "And what exactly are you going to do about it?" The next day, you stuff a smutty book in his bag with a note reading "what I'm gonna do about it."