I feel bad for Seonwoo because he wasn't raised properly and that's why he turned out treating others badly, because his parents were awful to him, he's basically reflecting their behavior onto whoever he chooses.
It's more like a defense mechanism for him....instead of letting people in on his life...he wants someone to love him but he finds it difficult to trust people thinking they were just using him, closing himself to others...it's not like he is treating them awfully but instead pushing them away while keeping up a friendly facade..and acts aggressively first so it'll look like he's the "hunter" and not the "prey" so he won't be looked down and look powerless like when he was a kid
I'M GONNA GO THROUGH THE DAMN SCREEN AND BEAT THE SHIT OUT OF YOU MYSELF YOU FUGLY ASS BITCH