After reports the pair were planning to wed in a hotel in Italy, Clooney teased the press by claiming they would tie the knot at his home on nearby Lake Como.
He then intended to stage a fake ceremony for the benefit of spying photographers.
Clooney explains, "Someone started a story that Brad was getting married at my place in Italy, so we tried to sort of spread the rumour for a while.
"I wanted to get a bunch of kids and dress them up in tuxedos. And I wanted them to send helicopters over my house. They'd be flying over, going: 'Get in closer!'
"But everyone figured it was made up."