I don’t think it’s a sad ending. In chapter 1, because of the unbuttoned shirt, I think YW was being forced into some kind of physical intimacy but he resisted and ended up escaping. From what he said in the same chapter — that he shouldn’t have hope or expectations — it seems he meant he shouldn’t hope for a romantic relationship with HY. He believes that because of his own “greediness,” things fell apart. But as we know now, YW is far from being greedy. It’s probably that someone made him feel like he was an obstacle. maybe HY wanted to leave the industry, or his mother was pressuring YW. YW is simple minded, while HY isn’t very expressive, and we still don’t know what happened between YW and HY’s mother. So, in chapter 1, either HY would harm YW which is unlikely, since HY loves him deeply or YW would be pressured and targeted by HY’s enemies after they had some kind of conflict.