this is stupid on a whole different level. MMC isn't dense, he just seems mentally incapable of any sort of intimacy
this girl who is literally throwing herself at him isn't just like some random classmate or childhood friend, but she's actually his girlfriend who has told him multiple times to his face that she wants to do this horny shit he claims to be obsessed with, so he has no excuse about "misunderstanding" or whatever bs usually gets thrown around to explain hyperdense MCs
rarely will i take umbrage to such a degree about what amounts to just another overused trope but GODDAMN cmon, at least write in some half-assed excuse about how the mc was lied to in the past so he has trust or intimacy issues or SOMETHING