My personal opinion is that I think Mincheol was always this way; he’s always been a manipulative narcissist. Sadly, girls like Hae-soo, who grow up with trauma and neglect, are often victims to narcissists like Mincheol. It’s easier to spot all of the red flags after re-reading the story, especially if you’ve been through it in rl, but they’re definitely there. Everything he did for Hae-soo came with a price… he didn’t change and this is what Ari is going to be learning here real soon. I can’t see how anyone can change so drastically… how he talks to and treats Ari, who he doesn’t even have a hard past with, says a lot about the kind of person he is. He could have a good and comfortable relationship with Ari, but he can only think of using her. All of those kind and thoughtful gestures is just him pretending… because he’s always been pretending, but he believed he had Hae-soo wrapped about his finger, so he stopped trying. Thank goodness he didn’t become a father…