call bluff

call (one's) bluff

1. To challenge someone to act on their threat or prove that their claim or boast is true, when one believes they are making a false claim or idle threat (i.e. bluffing). He insisted that he could run faster than me, but when I called his bluff, he suddenly said he had to go home.
2. To disprove a bluff. Whereas the first usage simply indicates a challenge, this usage indicates that the challenge resulted in the disproval. I don't know why he keeps making these outrageous claims. I've been calling his bluff for years and making him look like a fool.
See also: bluff, call
Farlex Dictionary of Idioms.

call someone's bluff

to demand that someone prove a claim or is not being deceptive. All right, I'll call your bluff. Show me you can do it! Tom said, "You've made me really angry, and I'll punch you if you come any closer!" "Go ahead," said Bill, calling his bluff.
See also: bluff, call
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

call (someone's) bluff

To demand proof for or respond in a challenging way to the claims or threats of another that one presumes to be false.
See also: bluff, call
American Heritage® Dictionary of the English Language, Fifth Edition.

call someone's bluff, to

To uncover a deception, or challenge someone to carry out a threat or prove a dubious point. The term comes from poker, where the players bet as to who has the best poker hand of them all. To bluff is to bet on a hand one does not believe is the best; to call means to match a bet, that is, bet an equivalent amount. When the cards are uncovered, whoever has the best hand wins the entire pot (all the money the players have put up). The term is American in origin and dates, like American poker, from the early 1800s. It was being transferred to other pursuits by the late nineteenth century; “Where shall we be when that bluff is called,” reads an entry in the Congressional Record (March 1896).
See also: call
The Dictionary of Clichés by Christine Ammer
See also:
  • call (one's) bluff
  • call somebody's bluff
  • call someone's bluff
  • claim
  • claim to fame
  • claim to fame, one's
  • a claim to fame
  • stake (one's) claim
  • stake a/your claim to somebody/something
  • call someone's bluff, to