Sangwoo killing stalking im not gay

i totally agree, i hate too sangwoo and i hate the fact that some people try to justify what he did because of his tragic past or because yon-bum was stalking him.

I'm sure not many of you noticed this, but Sangwoo isn't gay. How do we know that? At the beginning of the Manga, Sangwoo was walking with a girlfriend that waited for him to come back from the army. He also had 'something more' with Min Jieun before she died. And he probably had a girlfriend before.