Idiom

“Let the cat out of the bag”

MEANING:To reveal a secret.

HISTORY BEHIND IT: Market scamsters apparently attempted to replace pigs with cats; if the cat was let out of the bag, the gig was up. That’s related to why you don’t want to buy “a pig in a poke". You might not be getting the real item.

DIALOGUE:
- It was supposed to be a surprise party to Liam but now we have to change the plans.
- Why ? I think it's a good idea !
- It is, but Angela went and let the cat out of the bag.
- Oh, that's not good...