be caught with (your) pants/trousers down

1. to be suddenly discovered doing something that you did not want other people to know about, especially having sex.

Apparently he was caught with his pants down. His wife came home to find him in bed with the neighbour.

2. to be asked to do or say something that you are not prepared for.

He asked me where I'd been the previous evening and I was caught with my trousers down.

• lay someone to rest
• lay someone up
• lay something at door
• lay something at someone's door
• lay something on
• lay something on someone
• lay something on the line
• lay something open to
• lay something to rest
• lay the blame on
• lay the blame on someone
• lay the blame on something
• lay the ghost of
• lay the ghost of someone
• lay the ghost of someone to rest
• lay the ghost of something
• lay the ghost of something to rest
• lay the ghost of to rest
• lay to rest
• lay up
• lay waste
• lay waste to
• lay waste to something
• lay your cards on the table
• lay your hands on