Credit: Kevin Winter/Getty Images for Producers Guild ; Jon Kopaloff

She's easy like Sunday morning!

Notoriously raunchy director Judd Apatow tells he loved working with Jennifer Aniston on his upcoming comedy Wanderlust, in which she reportedly goes topless.

Aniston, 41, was "just easy" on the set of the flick (produced by Apatow and directed by David Wain), Apatow told Us at Saturdays' Producers Guild Awards in L.A. "That's why people like her and like working with her so much."

In the comedy, out this October, Aniston and onscreen husband Paul Rudd get into some R-rated shenanigans -- a nudist, hallucinogenic drugs and more -- when they mistake a hippie commune for a bed and breakfast.

As it turns out, Apatow and Aniston go way back. "I actually met her when I was a young man 20 years ago. She dated a friend of mine, so I've seen her from a distance on and off," Apatow explained.

"And she's always been an incredibly, funny person. She really is what she appears to be. She is just a great person who really is skilled at what she does and is hilarious!"