Heesung is nice to his partners and openly shows affection, but he tires of them quickly and moves on to the next one. Jaekyung most likely hasn’t had a connection with anyone else and although he treats Dan like dirt, we already know he’s grown attached. It would’ve been easy to let Heesung have his way, but JY brooded over it since they fought and this is basically throwing a tantrum and marking what’s “his.” I hope Heesung doesn’t do anything bad to Dan and is made into a reoccurring character. He may be a heartbreaker but I like that he wasn’t faking anything, we just couldn’t see the OTHER side to him