She was in cahoots with this guy who was smuggling drugs across the border.
Usage notes: usually said about doing something dishonest
in cahoots (with someone)
In close, often secretive or conspiratorial cooperation with someone. It turned out that the business tycoon was in cahoots with local law enforcement to have the investigation dropped.We've been in cahoots with a company overseas who can produce the product for half the price.
in cahoots with someone
If one person is in cahoots another, they are working together secretly to do something, usually something dishonest. He was accused of being in cahoots with the kidnappers. Note: You can also say that two people are in cahoots. They worked in cahoots to set the whole thing up without me knowing.