Ответ в теме: English idioms

Main Aditor

to let the cat out of the bag — to disclose a secret
1. From the warmth of her embrace he probably divined that he had let the cat out of the bag, for he rode off at once on irony. (J. Galsworthy)
2. I shouldn’t have let the cat out. But there it is — it’s a lucky start for you, my dear fellow. (A. Cronin)