All caught up

Let me break it down for you. If Sangwoo allows Bum to escape, there's a rather large chance for him to either go to the police and confess, or stay crying outside his door attracting police attention. Bum could slip and scream about how he doesn't care how Sangwoo is a murderer. Bum has nowhere to go. His conflicted mental status is telling him he loves Sangwoo, but is afraid of upsetting him. I believe that abuse from Sangwoo isn't as traumatic as his uncle's. If we're being honest here, Bum did break into Sangwoo's place and therefore, could have be murdered for being an intruder. Bum doesn't like the police, so let's say that Bum did run away, it wouldn't be for long due to the fact the police around there trust Sangwoo implicitly. Thereby meaning he could say they broke up and Bum tried to break into his house for revenge, so he attacked in self defense. Let's also not forget that Sangwoo is a quick thinker and marvelous actor. LOL

This I agree with you Especially on bums mental state, sangwoo has broken him to the point that he’s become completely reliant on him. However I’m more focused on why sangwoo favors him?hes killed every other person except bum. So I’m trying to figure out if sangwoo has become reliant on bum, it’s as if bum is a sponge or a mental cap for him. Remember when bum slit his wrist I was so captivated by sangwoo s response, so who is bum to him?

I think in his own twisted way, he sees Bum as the same. He's been abused too, so he knows what it's like. However, it could be that Bum's confessions are slowly seeping into his mind and he wants to embrace the feelings, but he can't due to his own mental issues.

I agree I think that emotion scares him because what has he been doing besides running from his past, and murdering. If he could be loved was it all for nothing. But again he has this mental disorder that kinda blocks that idea from even sticking.

Sangwoo kinda somehow sees his own mother in Bum so that might be stopping him from killing Bum as he does not want to be like his father,

So does that mean that his father killed his mother who was week and sangwoo killed his father. So could it be that this trauma has him living out that same day over and over again? They are on a strict schedule, with the same song playing and over again. I see he wants to not become his father but in a way he is like his father, only bum is his mother wouldn’t that make him protective? And the last chapter when he raped bum what does that mean?

Well it is implied that he almost or did drown his mother in the earlier chapters afterbum tried to commit suicide

Oh your right the bathtub scene. He’s got the cop off his back but I think the cop will dig deeper on his own and poor bum will end up dead or killing sangwoo

IMO, yeah it reminds him of his mother so his feelings were tinged with mother complex at the start but in his own fucked up way he has feelings for bum but somehow he doesn't want to acknowledge those feelings and he feels weird when bum says he loves him. So now, he's in the same state as his parents. Bum as his mother and he as his father and he wanted to do it differently, is what I think.