Domestic Kanojo route huh? Though the screws seem even looser on the FMC rn (DnK goes right off the rails, but the first few dozen chapters felt grounded). There's Tsundere, then there's going further beyond to Super Tsundere 3 here.
Can you really be surprised that a dude you tell to forget about the night of sex and confession you rejected and you tell not to talk to you around the house, and sees you around with multiple sketchy men may not want to just jump your bones on demand?
Shocking, a decent minded MC. What a weirdo.