'Four Christmases' co-stars Vince Vaughn and Jon Favreau are re-teaming for the tropical comedy 'Couples Retreat,' in theaters next year, and ET's hanging with the stars on their exotic location shoot!

Vince dreamed up the idea for the movie for the 'Swingers' pals, written by Jon and directed by Peter Billingsley (the child star of 'A Christmas Story' and a frequent producer on their projects, including 'Iron Man'), which follows four couples vacationing on the island getaway -- with one of the couples there to work on their marriage, the rest just tagging along.

"A bunch of average folks get a chance to go to an exceptional place and they go to Bora Bora," explains Vince. "It's a funny background and funny setting to see those guys kind of, [like] fish-out-of-water, go and try to be a little more groovy than they are."

"I have to say, when you get off the plane here and then ride across the lagoon, it's really breathtaking," says Jon, "There's really no place like this I have ever been."

Jason Bateman, Kristin Davis, Kristen Bell, Faizon Love, Malin Akerman and Jean Reno also star.

"It's like a playground for us," says "Sex and the City" star Davis. "There's jet skis, you dive off your deck into the ocean, there's sea turtles swimming under your house. I mean, it is heaven if you love this kind of thing."

Watch ET for more with Vince and Jon and the gang in 'Couples Retreat'!