One of the major reason on why I think Mincheol turned out into what he is currently is probably because of Na Haesoo being the main provider. It's not Haesoo's fault I know, but if you look for this scenarios in real life. Men will always cheat on their spouses who supported them at their lowest, probably to regain or inflate their ego with their younger side chick, to which Mincheol had done.
One of the major reason on why I think Mincheol turned out into what he is currently is probably because of Na Haesoo being the main provider. It's not Haesoo's fault I know, but if you look for this scenarios in real life. Men will always cheat on their spouses who supported them at their lowest, probably to regain or inflate their ego with their younger side chick, to which Mincheol had done.