Don't be a blabber mouth!

没必要说的话别喋喋不休地说”。

I can never tell Herry anything because he is such a blabber mouth.

我决不能告诉亨利什么事儿,他藏不住一点话儿.

Don't say anything to Bob unless you want the whole office to know. Bob's quite a blabber mouth.

不要对鲍勃说，除非你想让齐办公室的人都知道。他可是个多嘴的人。