George Clooney and Renee Zellweger joke they've been married for 28 years

George Clooney and Renee Zellweger cuddle up for a magazine cover - and joke that they have been married for 28 years.

The close friends - who were once rumoured to have been a couple - appeared together on W magazine to promote their new movie Leatherheads.

Asked by how long they've known each other, Zellweger joked: "Oh, God. Twenty-five, 30 years. We've been married 28."

Clooney then interrupted. "Twenty-seven. We lived together the first year. It was a lot of fighting."

Of their alleged domestic chores, Zellweger adds, "I fed the dogs and pigs. I vacuumed too."

On a serious note, Zellweger tells the magazine she was nervous about letting Clooney down on the film, saying she didn't want to "drop the ball ... to be the one who sucks."

"He doesn't even know how important his opinion has been to me over the years," she confides when he's out of earshot. "I don't want to disappoint him. "

"George is such a confident director, and he has no idea," she added.

'And he's a nice person. It gets boring hearing that, but it's true. Every once in a while you get the real good guy. You've got your Jimmy Stewart. You've got your Paul Newman. Now you've got your George Clooney."

But even during their serious talk about the film, the two can't help but crack wise. "In movies, so often the guy gets to be the one with all the answers," says Clooney. "In this one, she's the smart one. Which was incredible acting on her part."

"He's not kidding," she adds.