The line comes from The Wrong Trousers, the 1993 Wallace and Gromit short film created by Nick Park for Aardman Animations. In the story, Wallace's new robotic Techno Trousers are hijacked by the villainous penguin Feathers McGraw, turning a helpful invention into a runaway problem. The film won an Academy Award and became a beloved part of British animation, and the phrase has since travelled far beyond it. Online creators now use it as shorthand for any mismatched choice, borrowing its familiar British humour to signal that something has gone awry.