"I came over to help you study, so why did you pull me down in your bed"?
Silly teacher. Clearly she wants to study sex ed, yeah?
Still..."She'll change her mind if I get a bit forceful"? Ah, the usual phrase of a guy trying to take control of the situation only to end up going along with it in the end.
Great ending though. Resign...? Come now, surely that's not the way to go. In fact, take responsibility until the end and see her through to University. And then after she graduates...And then take her as a wife, right? That's just the natural flow of things.
Also I get the impression that since she feels her mum doesn't care about her, I think him praising her and patting her head and such made her somewhat happy and dependant on him.