Responses
I can see where you're getting at, and I actually think its because of your reason. Sure he might be missing Dojin, but on a deeper level, it could be trauma from his past. I really hope Fargo explains more of Hye-sung's past too ;-;
It's not just me who think's that the reason hyesung's so against doing the do is because of what his mother went through when he was younger, right? like it might still be eating at him and he believes that sex isn't something that should be enjoyed and that he'll be looked down upon if he starts to enjoy it. A lot are saying it's because he's "tsundere" and "stubborn" but I feel like this could also be a factor that should be added to the discussion...Then again, it could just be him missing Dojin hahah.