My Bias Appeared?!
I'm starting to hate the mc, like dude he's not an idiot, if he really wasn't sincere about liking you, he wouldn't make an effort in apologizing, (spoilers alert) let's say you have doubts and you've been hurt because of what he did, really hurt even, but you already told him that you know the truth and he should stop because the relationship he taught that you have with your cousin was actually just his misunderstanding. Now he's an idiot if he'll still approach knowing that fact, which is the only reason why he started all this shit. If you don't like him anymore then instead of avoiding him, tell him that you sincerely don't like him anymore, periodtt. Don't give any reasons also, cause that'll give him hope. For example, "I don't love you anymore because you've hurt me.", They'll just think that there's still hope in going back with you if they try hard and make an effort to get your trust back. Instead just straight up say you don't like him, nothing more, nothing less. And if he's the annoying idiot type who still doesn't gets it, or someone who's crazy that they'd take even your hate, tell them you don't feel anything about them, no hate, no love, no like, no nothing and when you meet them don't react, just continue with that behavior and they'll get tired and give up on their own.
The Duchess' Lewd Invitation