In my opinion, no he doesn't love him. Not even in a twisted way. I think he sees Bum as prey and smut (snuff) material. In my eyes, Sungwoo is a type of person who loves to play fucked up psychological games (hence him making Bum kill that other guy and possibly kill this recent girl). If you look up the word "sociopath" in the dictionary, his face would be right there.
i think sangwoo does have a twisted romantic feeling towards bum. when sangwoo thought bum disappeared (and that time when bum opened the door), he wasnt angry because his victim escaped. he was mad because bum said he loves sangwoo, because he has been submissive so far, bec sangwoo felt betrayed. sangwoo actually blushed when bum gave him a handjob for the first time, remember? although i believe that sangwoo loves bum, (as someone mentioned below), it's probably an unhealthy obsession.
so to answer your question, yes, i think sungwoo is in love with bum in a weird way.
i reckon (soz im aussie) that sangwoo doesn't really like him. he only keeps him because he reminds him of his mother, maybe he likes seeing his sanity slowly getting destroyed, as well as if he leaves obvs he'll get reported.
Is sungwoo in love with bum in a weird way?