Douglas 'comfortable' during sex scenes with Damon

Michael Douglas says he was "comfortable" shooting love scenes with Matt Damon in 'Behind the Candelabra'.

The 68-year-old actor portrays late American pianist Liberace in the film which focuses on the musician's secret homosexual relationship with his chauffeur Scott Thorson - played by Damon.

Although Douglas was very nervous about their romantic scenes, he says that once they got the initial kiss out of the way, everything was fine.

Douglas said: "Once you get that first kiss in, you are comfortable. Matt and I didn't rehearse the love scene.

"We said: 'Well - we've read the script, haven't we?'

"The hardest thing about sex scenes is that everybody is a judge."

Douglas was originally offered the role of Liberace in 2010 but had to put his career on hold after being diagnosed with stage-four throat cancer later that year and he admits he was so weak from the illness he couldn't do anything other than rest.

Speaking to New York Magazine, he explained: "When I was ill, I mostly lay on that couch.

"I watched a lot of sports, anything where I didn't know the ending … I did [miss working], but I was too weak to miss much of anything. I was stage four, and there is no stage five."

Although having cancer was the toughest period of his life, the Oscar-winning actor - who is married to Catherine Zeta-Jones, with whom he has two children, Carys, 10, and Dylan, 12 - insists he now has a new lease of life since beating the disease.

Speaking to Vulture magazine, he said: "Cancer does give you a new rejuvenation. I know what it's like to be down.

"Now it feels great to be back at work. Maybe that's the benefit of taking a break with cancer. Then people say: 'What's happened to him? Please come back'."

'Behind the Candelabra' is based on Scott Thorson's 1988 memoir and is scheduled to premiere on HBO on May 26.