You are the first to know. Mum's the word, or you would get fired.

你是第一个知道的，不要对任何人讲，否则你会被开除的。

But people have to know. That would be usury, and it's illegal.

但是大家需要知道这些。那是高利贷，

It's not how I intended. I didn't mean it.

我没料到事情会变成这样。我不是故意的。

Anyway, mum's the word.

无论如何要严守秘密。

重点讲解

Say nothing about it.

Mum's the word.

要求别人保守秘密，可以说Mum's the word. Mum(妈妈)其实跟秘密(secret) 本身没有任何联系，这里的mum来源于象声词Mmmmm,是紧闭双唇时发出的声音。字面上看,这句话的意思就是“你唯一能说的词就是mmmmmmm”，即“不要对任何人讲，要保守秘密” 。