tells him that he slept with daon. obviously, sunghyeon thought the worst. but, no matter how hurt and angry he was, he still stood up for daon when jaemin was saying bad things about him. when daon sleeps at sunghyeon's, daon finally confesses how he feels about him. (+)
among readers and I feel like a lot of people tried to twist sunghyeon's words when he saw the mark on his neck. It is true that sunghyeon could've heard daon's explanation, but I think his reaction was pretty realistic and understandable. (+)
is always there whenever daon needs someone to lean on. he gives him comfort and makes him feel like he can forget about the thoughts that constantly bother his mind. just like the author said, sunghyeon appears as a light in daon's dark life. (+)