Responses
I agree, and given that in chap. 17 Sangwoo gets so obviously jealous over Bum and that fat dude, he's probably "punishing" him for that too.
That's exactly what's in my mind. Well-said. cc: @baka-tan & u anonymous out there.
Spoiler! (Maybe)
Well, after the official translation I realised something.
Bum asked if sangwoo and jieun did it, sangwoo realised that bum was jealous so to make him even more jelly he sleeps with jieun in front of bum.
So next chapter we might see some action between sangwoo and bum, be it with bums okay or not ;-;
Dunno about the girl, maybe she dies...Maybe not.... I really don't care about her right now...