嘴严

只要你们 嘴严 实

(北京城就那么大) ── Previous context

“As long as you keep your mouths shut,”

嘴还算严吧 你觉得他能扛多久啊

(阿成) ── Previous context

“He's quit good at keeping secrets. How long do you think he can keep his mouth shut?”

可三法司的人嘴都严得很

(只有死人才能保住秘密) ── Previous context

“But the Three Judicial Offices are tight-lipped.”