Mokyeon is depressed, tried killing himself, passed out drunk, got hospitalized and Nanjo triggered his abandonment trauma I don't have a problem with him crying because it would be more weird if he was totally fine after what happened. But I totally agree about the obsession part, he got so obsessed with Nanjo to the point of almost suicide for a person he doesn't even know anything about? I know they're just going to end up together, but if the story was even remotely realistic it would be about realizing your self worth and not letting an obsession for someone you don't even know ruin your life.
That's why a lot of readers have mentioned the Borderline disorder problem. Because being obsessive about a person you don't even know or taking risk decisions such as suic** are commonly symptoms of this disorder.
Look, I like when a character is obsessed with another one but seriously, what does he even know about Nanjo besides how to fuck him?? Nothing. He doesn’t even know what car he drives or where he lives. Like maybe if he’d learned a few things about him during their time apart even just little details, I wouldn’t feel so iffy about their relationship. I wish the author would stop making him cry all the damn time like why is she ruining his character?? Okay, it was cute at first, but it’s been 8 chapters of him crying in front of him.