Responses
We'll se how how have they met :]
I don't think the adoped son feels guilty about their relationship. It looks like he's obsessed with Dongim (and the beginning of it was their first enounter I guess) and thinks he loves him.
From time to time it seems Dongim doesn't mind their affair and enjoys himself. Resentment appears after he murdered Dongim's parents.
oh. ... Adopted.. that took a while to sink in.
Adopted son covets the legitimate son, no sharing.
The legitimate son is playing mind games on the guilt the adopted son feels towards their relationship.
What's missing is HOW their relationship started, and to what extent it's wanted. We've gotten hints that the legitimate son is resentful, hiding behind a smile.
It's gonna be Toxic ya'all. (っ.❛ ᴗ ❛.)っ