What's (someone's) problem? phrase spoken informal
Used to express that you believe someone is being unreasonable.
Jack, what's his problem? The kids just asked him about his girlfriend, and he flashed out.
I ran to greet him, and he landed a punch on my chin. What's his problem?
Used to tell someone to go away and stop bothering you
1. That's a bit more expensive than expected.
2. That's rather unfair or untrue.