be caught with your pants down

be caught with (one's) pants down

To be taken by surprise; to be caught in a vulnerable (often embarrassing) position or situation. When the boss started firing questions at me, I was caught with my pants down and looked like a fool. I just hadn't considered all of those potential outcomes yet and didn't know what to say. We seriously underestimated our opponents on Saturday and were caught with our pants down.
See also: caught, down, pant
Farlex Dictionary of Idioms.

be caught with your pants down

BRITISH, AMERICAN or

be caught with your trousers down

BRITISH
1. If someone is caught with their pants down or is caught with their trousers down, they are discovered in an embarrassing situation or in a situation for which they are not prepared. The media was caught with its pants down after the story was proved to be false. He was shocked by the manager's walkout on Friday — and admits he was caught with his pants down.
2. If someone is caught with their pants down or is caught with their trousers down, they are discovered having sex with someone they should not be having sex with. He may have been caught with his trousers down in a brothel, but the real villains are those who threatened blackmail.
See also: caught, down, pant
Collins COBUILD Idioms Dictionary, 3rd ed.
See also:
  • be caught with (one's) pants down
  • caught with one's pants down, be
  • caught with (one's) pants down
  • be caught with (one's) trousers down
  • caught bending
  • caught
  • be caught off (one's) guard
  • catch (one) by surprise
  • with (one's) pants down
  • with pants down