American Idiom - informal : Let the Cat Out of the Bag ~ revealing a secret by mistake or without intending to. <br /><br />Examples<br /><br />Max was supposed to be surprised about his upcoming birthday party, but his girlfriend let the cat out of the bag, and he now knows.<br /><br />The HR department was informed not to discuss about the layoff, but someone let the cat out of the bag.<br /><br />“How could you let the cat out of the bag?” his wife asked. “Now, I have to find her again so I can take her to the vet.”<br /> Did you catch that? Trick phrase, the sentence is a practical situation.<br /><br /><br />Your challenge - when was the last time you or your friend “let the cat out of the bag” or did you let the cat of the bag?