dunno man, i agree with your first assessment… i think he was shocked and upset on Dan’s behalf.
What I noticed is when he saw Dan and Jeakyung told him to come closer, he gulped. Kinda sus and gives this impression that he wants to join as well (w/c in itself is disgusting) . But he's not as f.up like Jaekyung at this point. o（ｉДｉ）o
I don’t know. He hasn’t really been painted as a bad guy. Just the kind of guy who falls fast for cute guys. It’s not like anyone said he was being malicious or a player with the guys he dates. He even said he wanted to date Kim seriously. I actually thought he might try to help Kim once I realized what JaeKyung was doing.
Heesung can be sus but his reaction was pretty surprising. I legit thought he’d smirk and ask if he can join lmaoooo. But then again, I wonder if his look was more like “shit, I have to leave or else I won’t be able to hold it back” who knows