Give him a lesson on masterbation.
From Create Your Own Story
You shrug. The kid has to learn someday. So you tell him to take his pants off. He hesitates for a moment but quick pull both his underwear and pants in one fluid motion. You do the same but also take off your cum stained shirt copying you Erza takes his shirt off as well. The boy stares at you waiting for the next instruction. What do you tell him to do?