Generous

Jostin has given you good entertainment, it would be to cruel to punish him too much. Amina vanishes the memory of the fucking from the students mind, but you can't leave Jostin unpunished.

"From now on, Sir, whenever you have lustfull thought about a student you will have an instant erection and then 10 seconds later you'll cum in your trousers."

Jostin stammers, he dresses and brings order to the class somehow. You sit back down at the back of the room. He continues his sex education lesson, drawing diagrams on the board trying not to catch the eye of any female pupils.

Eventually he sees Carly who is showing a little too much cleavage, "Carly, I just..." you see his trousers bulge and then a damp patch appear at the front. Jostin runs out the room as the bell rings.

You laugh and proceed to the next lesson..