The teacher is so unnecessarily gross and creepy that it actually completely turned me off to this series.
If the fmc can't trust men and can innately tell when they're trying to get in her pants, that's on those men. Clearly she does fine with the mc, so the problem is that she doesn't have enough decent men around her who wouldn't instantly see her as an object. What kind of brainlet would suggest that she needs to be sexually assaulted to "cure" her "affliction"? I don't even... like it doesn't make any sense to the point that I don't even see what the author was going for. It's something I would expect out of a misogynistic grifter's mouth, not a woman's writing.
I could excuse it as typical "manga nonsense" if the teacher character was completely dismissed (although why even include her at that point?). From what others are saying though, the mc does go along with her idea to move quickly, even if he doesn't actually assault fmc. I think it actually says a lot about the "supposedly good guy mc" that he would even take her words into consideration. I don't even see the point, it's not like there wouldn't have been romantic evolution without the teacher character. Now though, no matter where the story goes it'll be tainted by the fact that the mc was so easily swayed by the words of his fuckup of a teacher. To me at least.