Say "I'm the boss"

"Being a smart-ass is gonna cost you, twerp." The bully clenches his fists and moves toward you, but just before you are about to get your face pummeled someone calls out to him.

"Hey, man, stop messing around with that geek, we found some fireworks in the forest and we're gonna go blow up ant hills!"

The bully looks over at his friend and then glances back to you. "I'm not going to bother now, but I'll really pummel you next time, Nerd!" And with that the bully backs off and walks out of the school. You look down the hall, watching students walk to different classes. You decide to visit one of your classes.