okay so

the boss strangled young dajeong because he didn't want them to be brothers cause he just realized he may have had a crush on him and couldn't think of anything else to do in the heat of the moment to make the marriage not hold...?
and now we're seeing that dajeong was already living with the boss before the events of chapter 1 of the main story soo the reason why the boss went after lee hyuk (the bottom of the main story) was because he looked like dajeong and had a muscular body like him too
so the boss has liked dajeong since he was a kid but never acted on it..interesting