Oh yeah. You'll realize that Jiheon is VERY stubborn. But Jaekyoung is more stubborn and knows how to corner him VERY well.
I would say that JK is rather gray, but it's something that Jiheon needs to just get him to stop being so stubborn. You'll see Jiheon is rather afraid. He sinks his teeth into refusing to budge because he's been used to much and is afraid to be abandoned.
JK proves to him that he won't ever leave him.
JK is legit one of the biggest simps I've read.
He's gray in a sense that he kinda forces Jiheon to do things that he finds uncomfortable or refuses to do. But Jiheon is so stubborn it only hurts himself.
Jaekyoung can be rather harsh with his words and you think, "omg he's such an ass" at some points... But then he explains it better and you're like "oh... I guess I didn't think about that."
Just a wee small spoiler on their personalities:
JK calls JH selfish at some point and that he keeps things to himself, that he doesn't think about the other person and how they would feel...
Jiheon is literally hurting himself because he doesn't want to burden JK and he wants to be with him, but then JK says along the lines of, "you're hurting yourself and that hurts me. You're not thinking of yourself and don't ask for my help. I can help you and we can figure things out together. You don't have to do it alone."

The agony, how long is this going to take (╯°Д °)╯╧╧