Who's asking?

Who's asking?

Why are you asking me this question? Used to express one's suspicion of another person's motives. A: "Excuse me, do you know a person by the name of Ed Brandon?" B: "That depends. Who's asking?"
Farlex Dictionary of Idioms.
See also:
  • bandage up
  • pearly
  • answer for
  • away from (one's) desk
  • away from desk
  • hit the rock
  • babysit with (someone or something)
  • lay cards on the table
  • lay one's cards on the table
  • lay your cards on the table