The business of someone you're speaking too. Not your problem.
I didn't fuck with that nigga's cousin, that's all you.
The term "All You" is a term that can used in a number of ways. It can be used to signify a positive result in favor of the person who says "All you" or to whom the term is directed at. The term can also be used an adjective. The term is originated from the infamous "Chun Szeto" crew.
Person 1 : Damnnn look at that hot girl walk by!
Person 2 : All you !
Person 1 : I just aced my final exams without studying.
Person 2 : All you!
Person 1: I just got a job at Wendy's.
Person 2: Wendy's all you!
Person 1: I was running the pool table all day.
Person 2 : Pool table all you!