Keep your pants on!

keep (one's) pants on

To remain calm and composed while waiting for something. Usually used as an imperative in the phrase "keep your pants on." If all those investors would just keep their pants on instead of jumping ship at the first sign of danger, the company might have had a chance to recover from the poor reception of their latest hardware. A: "Bill? Bill? Hey, Bill! C'mon, what's the hold up?" B: "I'm coming, I'm coming. Sheesh, keep your pants on!"
See also: keep, on, pant
Farlex Dictionary of Idioms.

Keep your pants on!

verb
See Keep your shirt on!
See also: keep, pant
McGraw-Hill's Dictionary of American Slang and Colloquial Expressions
See also:
  • cool it
  • Cool it!
  • cool it, to
  • chill out
  • keep at
  • keep at (someone or something)
  • come off it
  • Come off it!
  • count in
  • carry on with (something)