Douglas has bounced back from his cancer battle last year (10) to start filming the big screen story of the flamboyant gay entertainer's life.
Damon has abandoned his action man image to play Liberace's younger partner in the film, and is adamant his kissing scenes with Douglas almost make up for the fact he didn't get to make out with the star's beautiful Welsh wife in Ocean's Twelve.
He tells People.com, "I never thought I would get to kiss Michael Douglas. I kind of think of it in algebra terms, back to my high-school days. It's like the transitive property - by kissing Michael Douglas, I am making out with Catherine.
"I was actually kind of upset that I never got to kiss Catherine. But now I get to kiss Michael. I thought it would have been better if I could have at least kissed them both."