Responses

No no, u misunderstood. Him killing his uncle was a mistake (probably), or an accident (maybe), but he's hiding it from sooyoung. Howeverrrr, the incident with sooyoung being targeted and being stabbed, big daddy knew about it and let it happen so that it will teach sooyoung a "lesson" to stop putting himself in danger and also to manipulate him into needing him.
"I'm not hiding anything"
narrator: he IS hiding things, he killed your uncle and almost let you get killed just for fun