I'm soooo conflicted

I'm pretty sure they had a pedophilic relationship, as he views his mother with an almost absurd type of fear, and she had a really irrational reaction to the confession letter Sangwoo received as a child.

Wait im confused someone please explain

In the previous chapter featuring a flashback to Sangwoo's childhood, it shows his mother having a contradictory reaction to a love letter Sangwoo receives in school, almost as if she was jealous. Again, during Sangwoo's dream (with the maze) you can see how for a moment Sangwoo's mother is replaced with the mirage of Bum, whilst he is hugging his mother's hips. This hints at a explicit relationship his mother must have had with him as a twisted type of release from all of the domestic and emotional violence she suffered at the hands of Sangwoo's father. Sangwoo is conflicted in his feelings for his mother, which is one of the motivators of his parents murders, moreover there is a sense of foreboding and cynical remorse in the way Sangwoo approaches his relationship with Bum, as he sees his mother in him, thus why time to time he tends to lash out at Bum and push him farther, as a way to "get back" at his mother. Bum in turn shares similar traits with his mother, such as he is subservient, willing to please and go to extreme lengths for Sangwoo. This diety-like devotion makes Sangwoo an egotist in a penal and abusive relationship, thus we can see the "cycle of abuse" how Sangwoo has become who he has detested the most -- His father, and Bum is the persona of his meek willed mother.

that's my interpretation at least ╮(￣▽￣)╭

ohhhhhhhh