Wow, I have mixed emotions here.
I think Haru is right, there's no much he can do and there's no point in losing the short amount of time he has in Kyung. Just think about what he said and imagine Danoh's death. What if she dies slowly in front of Kyung? Every moment with her would force him to remember over and over the memories of his mom and everything that happened in the past.
It's clear, more than ever, that he didn't want to be with her not just to defy his father, but also because she's too similar to his mom. It gets all the sense now that he didn't like flowers since it's the typical symbolism of abusive men and yeah, thinking on that, and in the fact that he did the same to Danoh I can just be in awe. Wow.
Tbh I'm not even angry at him, I feel like my boy will have a hard time from now on, probably harder than anybody else because he's not willing to change.