HS is bitter, doesn't talk about what bothers him, never clearly tells JW that he should stop his bootycalling him, and no, he has never taken JW's feelings seriously because he's not allowing real feelings to be out in the open. JW is likely in love with HS. Again, not maturely, but HS carries on being FWBs and then says he hates it later. Pick a lane, have courage in conviction.
But continue being insightful about how I should a dictionary. XD
The point is that HaeSoo and JooWon do not have a developed relationship. It's based on game-playing and lust. They don't ever really communicate. So, yes, JW is selfish and an egotistical, possessive guy. But HS got his rocks off on these traits for years.
If HS doesn't want this anymore, he has to say so and not be a hostile, passive aggressive bitch about it. Regardless of whatever the fuck relationship they have, it's still a relationship that both of them have been in denial about since day 1. HS needs to grow up and take JW seriously.