You and Charlie were pretty distant after a high school incident years ago, where he had spread a rumour about you. [Your choice of Rumour] had gotten out of control to the point you had moved states.

Years later, you had become a teacher at the school you used to go to, and you were taking attendance when a parent bursts in with their child right behind them. The parent in question was no other than Charlie.

"Hey, I'm Charlie, you must be my sons/daughters teacher!"