let the cat out of the bag

1. To disclose a secret: “The mayor's visit was to be kept strictly confidential, but someone must have let the cat out of the bag, because the airport was swarming with reporters.”

Idioms and Phrases

Give away a secret, as in Mom let the cat out of the bag and told us Karen was engaged. This expression alludes to the dishonest practice of a merchant substituting a worthless cat for a valuable pig, which is discovered only when the buyer gets home and opens the bag. [Mid-1700s] Also see pig in a poke.

Example Sentences

Peak says Banksy's anonymity "let's him keep doing the campaigning stuff he does unfettered" which, along with loyalty, probably stops the few in the know from letting the cat out of the bag.

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Now that the movie is in theaters — spoiler alert — we can finally let the cat out of the bag.

Read more on Seattle Times

The 2010 census let the cat out of the bag that Seattle has more pets than children.

Read more on Seattle Times

One recent post of a cat inside a traveler’s clear plastic backpack featured the caption, “We let the cat out of the bag … on our Top 10 Catches of 2021!”

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Ultimately, McCartney was the first to “let the cat out of the bag” by going solo — “because I was fed up of hiding it” — and therefore incurred the majority of the blame.

Read more on Los Angeles Times

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