
Taesoo (red) is in love with Chunwoo (black)... they are also both just horny & lazy daters. Taesoo comes across possessive because obviously he's jealous & he wants Chunwoo for himself. Chunwoo obviously doesn't want that... he just likes fucking him because it's easier than finding someone new.
Ho-In (brown) shouldn't have to deal with any of this but the ball is literally in Chunwoo's court because he has all the power to choose between the two guys. But he also doesn't know that Ho-In really likes him...yet.

I really can't explain it but i think there was a point where Chunwoo liked Taesoo and they were in a relationship. But Taesoo did something that broke whatever relationship they had. They're still holding on because they still feel something and because they are accustomed with each other but its not the same anymore. I think Chunwoo's anger has a deeper cause.
This is just my opinion and i may be wrong soo ┑( ̄Д  ̄)┍
Also i may have misinterpreted what you were saying so if that's the case, im sorry.

Honestly I feel like we're in the same boat. There is something deeper that we do know about their past relationship. If anything its going to be awhile before the author even explains (you know considering the raws). However don't ever think your opinion doesn't matter because it does & I like when people put in their input.
The artwork is great altogether but we know where the artist spends their most focus