But he didn't. The whole flashback is about him holding his own desires above her wellbeing. Even in their first time there was the red flag of him not stopping after she started crying (we read him hating himself for it, but HE. STILL. KEEPS. DOING IT). I think that's actually the point. That even at his sweetest he was still greedy and selfish. He wanted her more than he loved her. Everyone says that they don't get how he could change so much... But there we have the seed of everything. She endured because she loved him, but it was still a red flag. She's naturally self-sacrificing... And he learnt that he could be as selfish as he wanted and she'd take it. And he ran with that.
i’m crying, can the author stop with this flashbacks? mincheol loved her, genuinely and look what happened, ah fuck this shit it’s too early to relapse FAAAAAWK i came here for some lovey-dovey shit between haesoo and taeha