Responses
it's his mom right? she seems to be the major cause to his curiosity of sex.
The manga just said it was the mom. His mom was super obsessed with him staying innocent and said not to be like his dad.
I know, I'm just saying that it could be an even more specific event.
It has something to do with the student's past ,some sort of trauma. I suspect that its some sort of punishment to himself. I've seen cases like this before.