Their engagement was to be a secret but the ring on her finger let the cat out of the bag.

他们俩订婚原本想保密的，可是她手指上的戒指却把这个秘密泄露出来了。

youdao

It's a secret so please don't let the cat out of the bag.

这是一个秘密，因此请不要泄露秘密。

youdao

Therefore, 'let the cat out of the bag' must mean something like 'reveal a secret' or 'tell a secret'.

因此，“let the cat out of the bag”一定是“揭露秘密”或“泄露秘密”之类的意思。

youdao

If you tell about something that was supposed to be a secret, we say you let the cat out of the bag.

VOA: special.2009.09.27

Although the identity of the winner is meant to be a closely guarded secret, the Cameroon striker let the cat out of the bag following their midweek friendly win over Senegal in France.

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