Bana

I'm not sure myself. It's kind of confusing but I think it was because Yujin felt he'd fall hard for Hunter and he thought that Hunter didn't really like or love him, Yujin was more like Hunter would eventually abandon hin too when he would be bored and instead of expecting something out of their fuckship, he chose to ran away before he could catch feelings or let Hunter's affection mess up his head.
It was that kinda plotline.

Just another BL with massive Communication gap, which could be 40episodes less + more fluffy if they talked. (〜￣△￣)〜

(sorry for the long explanation !) from what i understand, theyre an avoidant x obsessive dynamic. yujin is extremely avoidant and aaron is very obsessive, Yj probably left because he knew he was growing too attached to aaron and he did not want that. he doesn't wanna be tamed. he also has an inferiority complex seen in past chapters when he couldnt look in the mirror when he was having sex with THE aaron hunter since he was just an unknown singer. he's grown up poor so the whole relationship with aaron makes him feel like they really shouldn't be together. Then there's aaron, He's very possessive in a way. its not like "you're mine so dont have sex with anyone else," rather "you're mine so i'll make you obsessed with me until you dont feel the need to have sex with anyone else" and he sees yujin as someone that needs to be tamed. TLDR: yujin left because he's the most avoidant mf despite being offered the world

In short, Yj is self-deprecating and Hunter is obsessive possessive. Lol, thank u for this insight

Ikr, I scrolled past this chapter coz their dialogues are not dialoguing. They could just be honest with their feelings and we could all enjoy it