you have got to be kidding (me)

you have got to be kidding (me)

You cannot be serious; I don't believe it; this can't be true. A: "Did you hear that Sam got promoted to General Manager?" B: "You've got to be kidding me! That guy couldn't manage his way out of a paper bag!" Oh, you have got to be kidding! How can the traffic already be so backed up?
See also: have, kid
Farlex Dictionary of Idioms.

You've got to be kidding!

Inf. This cannot be the truth. Surely you are kidding me! Bob: Sally is getting married. Did you hear? Mary: You've got to be kidding! Bill: I think I swallowed my gold tooth! Mother: You've got to be kidding!
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • You've got to be kidding!
  • you must be kidding (me)
  • you're kidding
  • you're kidding (me)
  • (Are) you kidding (me)?
  • who am I kidding
  • me
  • aside
  • no kidding
  • No kidding!