守口如瓶

tā duì zhè shì shǒu kǒu rú píng

他对这事守口如瓶。

He kept a tight lip about this.

wǒ xiǎng shuō dàn tā ràng wǒ shǒu kǒu rú píng

我想说，但他让我守口如瓶。

I wanted to talk, but he told me to keep my lips buttoned.

wǒ men bèi yāo qiú shǒu kǒu rú píng

我们被要求守口如瓶。

We have been asked not to say anything.