don't call me sir, I work for a living

in the line of duty

As part of or while performing official duties, usually of the militar…

don't hold your breath

Don't wait. Said cynically to suggest that what has just been mentione…

don't knock yourself out

Don't overexert yourself (in doing something that does not require muc…

don't go there

Do not broach that topic.

don't get someone started

Used to attempt to avoid or abbreviate a discussion that speaker or he…

don't give up your day job

Somewhat sarcastic but usually good-natured advice used to criticise a…