Not only do they take years, Swooney Clooney has been known to dive into skips to orchestrate pranks on his friends.
The actor once convinced his friend Richard Kind (he played muppet Paul Lassiter off Spin City) a "horrible" painting he found in the rubbish was all his own work and made him hang it in his house - and only told him the truth six years later.
He told Entertainment Tonight Canada: "I got a painting out of the garbage that someone was throwing away, it was on the side of the road, I picked it up and I took it home and I signed my name to it. And my friend Richard Kind who was on Spin City (got it, thanks George) - big Richard Kind - on his 40th birthday, [I gave him] this huge horrible painting of this naked woman, terrible painting. I said, 'I've done a lot of paintings, but this is the first one my art teacher is really proud of.' And he had to hang it, I was best man at his wedding, he had to hang it on the wall of his apartment. I left it for about six years before I told him."
Matt Damon recently relived how he was convinced he'd gained an alarming amount of poundage after George convinced the Monuments Men costume department to take in his clothes slightly every day. Sound. However, the 52-year-old star insisted that's just a minor prank compared with some other gags he is planning.
He said: "That was just a little something I did on the side. I've got some others cooking. I do pranks that last for years." Or in the case of his girlfriends, usually two years. Just ask Stacey Kiebler, Elisabetta Canalis, Sarah Larson, Krista Allen... Kelly Preston... Lisa Snowdon was the exception, he kept her on the go on-and-off for five years.