beta
Yun-ho is definitely immature and lacks communication skills, which he needs to work on. But remember Haewon also wasn't sure of his feelings for Yun-ho until he basically threaten to leave. Their relationship dynamic is unstable for sure.
I think Haewon shouldn't force himself to change b/c Yun-ho is bothered by his actions, but find a way to reassure him that his feelings are real for Yun-ho. I believe that's what Yun-oh is struggling with. Doesn't help that he's seen how Haewon was in his past relationships. So in his mind he thinks that once Haewon feels like Yun-oh is too much he would dump him. Which is why he doesn't like it that Haewon is changing himself for him. And has a hard time believing that Haewon seriously likes him.
It's on both sides that need to communicate better. Not one or the other. Haewon over explaining himself about the smoking situation didn't help his case. It just made Yun-ho feel even more like he's forcing his feelings on to Haewon making Yun-ho feel like shit.
Also Haewon needs to stop acting like Yun-ho is still that afraid little child. He's coddling Yun-ho too much not allowing him to grow up. Which probably also feels stifling to Yun-ho.