
It's not unrealistic reaction by ml , you can see it in real life how people some people who act like mannered do something like this when things don't according to them or cause betrayal to them . And it's realistic response as a victim then mc try to pursue him even after that. Only unrealistic thing will be if author try to make them a endgame as a couple .portraying this kind of situation is only ok when your theme is not only a a love dovey webtoon category.

The ending is good , the whole self reflection thing and growth of character Make the story even better. The mc character is different and how he learnt to deal with the situation and accept his own short coming. And like the part where he didn't give up when ml tell his past like other manga where mc become soft hearted and forgave immediately. The mls also likeable in this story. I like how they show the time skip .
That's mean mc with someone else in his younger days. And ml know he likes men