Get ready for some of the unsexiest nudity of the year in "Wanderlust," Paul Rudd and Jennifer Aniston's new comedy about suddenly unemployed urban dwellers George and Linda who unexpectedly find themselves at a hippie commune that's not only clothing optional but polyamorous. Their introduction to the clothing optional part is initially through Joe Lo Truglio's full frontal nudity (though, to be honest, the actor wears an impressive prosthetic penis throughout the film). "[Whole Lotta Penis] was the original name of the film," Rudd jokes.

Though director David Wain claimed that Lo Truglio doesn't actually have that many nude scenes in the movie, they definitely have a lasting impact. Paired with one group scene featuring actual nudists (running in slow motion, too), the end result is that "Wanderlust" feels like one very funny anatomy lesson. "Somebody said yesterday this is a balls out comedy," says Rudd. 

Even Aniston has a topless scene (don't get too excited -- it's digitally blurred out), but all the nakedness started to be no big deal to anyone on the set, including the stars. "With anything you get desensitized," says Aniston. "Think of the beaches in France. Topless, when we go over there..."

"After five or six hours, you hardly notice it anymore," Rudd shot back. 

What may stick with audiences longer than memories of Lo Truglio's junk is one scene in which George (Rudd) tries to psych himself up to have sex with a nubile and willing Eva (Malin Akerman) by spouting groan-inducing dirty talk at himself in a mirror -- and, later, to an increasingly disgusted Eva.

Rudd improvised most of the scene (and it continues over the end credits, so don't leave the theater too soon), and didn't hesitate to capture his character's goofy-but-gross approach to seduction. I thought it might have been difficult for Aniston to cuddle up to Rudd the next day, but apparently not. "I loved seeing him the next day," she said, with just a hint of a smirk. "That was a treat. I think everyone loved seeing him the next day."

Considering that the mirror scene was also shot the same day as a scene in which Rudd sits on the toilet, only to find members of the commune (which has no doors) taking this as an ideal opportunity to have a chat, there was a sense of the production diving into the deep end right away. "I remember looking around and thinking a lot of the crew were actually confused as to what we were shooting," Rudd recalls.

But they didn't have to worry, as Wain and co-writer Ken Marino have impressive comedy credentials ("The State," "Wet Hot American Summer") and had comedy titan Judd Apatow on board as a producer. Adding some extra comedic weight to the production was M*A*S*H icon Alan Alda's appearance as a spaced-out hippie (also look for another 70s star, "Alice"'s Linda Lavin, in a small role). Apparently he was fun, too, as he not only joined in the cast bowling party, but managed to bowl backwards.

Of course, Alda might not be Aniston's most memorable co-star -- her character also has a dalliance with Seth, played by her off-screen boyfriend Justin Theroux.