they have their own twisted kinks apparently
Wasn't this the first time it happened though?
Yup
I believe the girl in the basement. Implied.
He probably had sex with the girl in the basement but not in front of Bum. If he did have sex with her it would have been before Bum arrived, as Sangwoo killed her shortly after Bum's arrival.
I know this manhwa ain't about love. Just twisted emotional and mental issues...But damn! How many times is the hot psycho Sangwoo going to mindlessly f*ck women in front of Bum?! This girl will probably get gutted by Woo or maybe finally Bum will snap and kill her for him which is probably what he wants Bum to do!!! I guess it says a lot about me that it pisses me off more that he fucks women hurting Bum in the process than killing people in front of him. ╮(￣▽￣)╭ Lol