I think that's a you problem.
A way to say 'You’re the one who messed everything up. I’m not the problem. You are.' It’s the go-to line when you're too lazy to explain why you're mad, but you still want to show you're right.
'I think that's a you problem.', said when your friend broke your phone and didn’t even apologize.
'I think that's a you problem.', said while you were eating the last slice of pizza and your brother asked for it.
'I think that's a you problem.', said when you missed the bus because you were too busy playing video games.