Not at all. He's neither a jerk nor selfish. If he was selfish and a jerk, he could've gone to catch Ted chang and on his way to Seoul by now. But he abandoned that to go save the FL. He's constantly attentive to FL and can even notice slight changes in her mood. He has done everything to protect her from harm but she's not listening at all. I would prefer them to be together but honestly, I think ML deserves better. He is an orphan and probably didn't know how to express love growing up and as a detective he always among violence. He even saved the coffee girl he didn't have to.
2nd lead hasn't done anything for FL. it's always FL who comforted him while it was the ML who was actually did everything for her. and people forget ML literally lost his little brother figure who he really loved in his own way and he wants to catch the killer for him. He's the best character in this series not even FL is just dumb for not listening and gets herself and everyone around her in trouble.