'Wanderlust' Co-Writer Ken Marino on Casting Paul Rudd and Jennifer Aniston (Video)

"We had Paul in mind when we started writing it, and Jen was kind of on our dream list," Marino, who co-wrote the script with director David Wain, told THR at the premiere.

In Wanderlust, Ken Marino plays Paul Rudd’s character’s older brother. His loud-mouthed, neurotic character Rick takes in Rudd’s George and his wife Linda (Jennifer Aniston) after George loses his job.

Marino, who also appeared in MTV's The State and Starz’s Party Down, isn’t only a star in the film, but a co-writer. He wrote the project with director David Wain. The duo also penned 2008’s Role Models.

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At the premiere for Wanderlust, Marino told THR that he and Wain were roommates in college. “And we just have a good time together and we make each other laugh,” he said.

“We just sit in a room together and start banging out stories,” he said. “If he makes me laugh, then it goes in. If I make him laugh, then it goes in. If we read it again later on and it still makes us laugh, then it stays in.”

Universal’s comedy, produced by Judd Apatow, reunites Aniston and Rudd, who appeared on Friends together, and also starred in 1996’s Object of My Affection. In Wanderlust, they play a married Manhattan couple who move to a hippie commune after George loses his job.

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“We had Paul in mind when we started writing it, and Jen was kind of on our dream list,” Marino said of casting the two leads.

“When they stepped into it, their instincts and their choices were spot on,” he added.

Aniston also spoke to THR at the premiere, saying that it was a joy to work with her friend Rudd again. “We just have a true affection for each other and I just feel honored any time I get to work with him," she said.

Wanderlust, which also stars Malin Akerman, Alan Alda and Kathryn Hahn, opens in theaters on February 24.

Twitter: @Beccamford