Trying to find the manga about a boy who attends a school that trains them to become experts in a certain service/sex industry. There was a rule like they cannot have relationships with each other or the staff or else they'll get kicked out. However, the chairman(?) or one of those big guys got involved with him anyways.

it sounds like Ai to Yokubou wa Gakuen de

who needs drugs when you got yaoi

-such a late reply- but

XD Yes thank you so much!