For people wondering "omg why doesn't he tell anyone, that was rape" and everything
But realising it was indeed a rape takes a lot of time first. You can even deny that for a long time and realise years later.
Also he feels guilty towards his boyfriend, and his teacher said HE was the one who initiated it.
I understand why he acts like this. It's still a better idea to talk about it to someone, because that would help him get through that. Maybe not his boyfriend in a first time, a close friend would be better, but sadly he doesn't seem to have such close friends..