ABC News' Thea Trachtenberg reports:

Matt Damon takes on a risky, risqué role in "Behind the Candelabra," in a side of the Oscar winner we haven't seen before, adorned with feathered hair and wide lapels.

"To me this is the dream job," Damon told ABC's Elizabeth Vargas in Cannes, France. "It was a chance to be in the front row while Michael [Douglas] turned in this amazing performance."

Douglas plays the flamboyant Liberace, and Damon, the man best known as super-spy Jason Bourne, is taking on a very different mission as his young lover.

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"It was a very deep love affair," Damon says of Liberace's relationship with his character, Scott Thorson. "You know, it was a marriage in a lot of ways for these guys."

And although Douglas may get the splashier wardrobe equipped with capes and furs, Damon still gets some rhinestones of his own wearing a jeweled mankini.

"Yeah, I have never had this much fun," said Damon. "It has jewels encrusted all over it … A jewel encrusted mankini."

When asked what it was like to shoot the love scenes with Douglas, Damon replied, "The more challenging stuff was really selling the intimacy of a relationship that's kind of a deep love affair. That stuff is actually, to me, way more intimate than 'All right, I'm going to straddle you right now and plant one on you for exactly seven seconds. You ready? Here is comes.'"

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Damon's off-screen romantic life is much less salacious, being married to Luciana Barrosso for seven years now. Just last month the couple had a private celebration on the island of St. Lucia in front of family and special friends to renew their wedding vows, and Jimmy Kimmel officiated the ceremony.

"We were looking for the perfect blend of depth and humor and humanity and he was the right guy for the job," Damon explained.

Damon has one of the longer-lasting relationships in Hollywood, and jokes it's probably because he and his wife live in Manhattan, not Hollywood.

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"We get left alone by the paparazzi and that stuff, so the celebrity thing doesn't really weigh on us," Damon said.

Close friends of his, Ben Affleck and Jennifer Garner, aren't so lucky however.

"Yeah, Ben and Jen, they don't do anything to court it, other than their job, which is the same as me," Damon explained. "It just happens for some people that way and I'm lucky that it's not that way for me."