George Clooney got his own back on Brad Pitt for making him look like a egomaniac on the set of Ocean's Twelve - by making him drive through rush-hour traffic with a sign suggesting he was lacking in manhood.
Clooney wasn't happy when he realised he'd been referred to as Mr Ocean on the set of the film in Italy for a full month because Pitt sent a memo to all crew insisting they call him by his character's name.
So he waited until the final day of filming before teaming up with his other co-star Matt Damon to play a practical joke on Pitt.
Damon says: "Brad was about to drive off and George came up to say goodbye. Brad was sitting in his car and George kind of tapped the car with his hand and said: 'All right, take care.'
"When he pulled his hand away, he'd left a bumper sticker that read 'Small Penis Onboard'. So Brad drove through rush-hour traffic in LA with it, and all these people were looking at him and waving."