catch (someone) with his pants down, to

catch (one) with one's pants down

Fig. to discover someone in the act of doing something that is normally private or hidden. (Literal uses are possible.) Some council members were using tax money as their own. But the press caught them with their pants down and now the district attorney will press charges.
See also: catch, down, pant

catch (someone) with his pants down, to

To embarrass someone, to surprise someone when he is at a disadvantage. The term is American and there are several theories about its origin. One holds that it comes from a husband catching another man with his wife. Another claims it refers to an enemy catching a soldier relieving himself.
See also: catch, pant