Responses
At this point if it was shown in a flashback scene that as a child he saw his mum forced to give his dad a blow job, or witnessed his mum being raped, it wouldn't be surprising. I am liking this series best, as it's showing more of Sangwoo's background and how this has influenced him. And yes, at this stage in the plot he is really coming off as being exhausted and breaking down.
"I win" = "I'm not like my father, mum, so you were wrong"?
I mean, he started acting "nicer" to Bum ever since he dreamed/hallucinated his mother telling him he was just like his father. ...And, anyone noticed how he opened the tabs to the max in order to conceal the noise of his puking? He didn't want Bum to hear, he wants him to think he's still in control. But he's not: he's acting recklessly and seeing his victims everywhere, he's clearly at breaking point. I guess we can expect him to do something even more rash some time soon.