Jake Gyllenhaal must be pretty tired of talking about his naked body.

The actor, 29, who appears naked on Entertainment Weekly with Anne Hathaway, revealed even more about the abundant nudity on set for Love and Other Drugs on Wednesday's Late Show with David Letterman. "We were pretty experienced," he said of their time spent filming sex scenes together. The two also played husband and wife in Brokeback Mountain.

"We had cinematically been de-virginized together," he said. But despite all the challenges he's faced in his acting, one thing stood out as the most difficult. "The hardest thing has been pretending to be turned on by Anne Hathaway," he said. "It's acting Dave, you gotta commit to every moment."

Letterman seemed more interested in the nudity. "You get excited when you first, you see her … she is undressed," he said. "But what you don't think of is that we're going to see you [naked]. You know, that didn't occur to me." Gyllenhaal answered sardonically. "The funny part about that situation, usually, when people have sex — whatever, intercourse — both people have to take their clothes off," he said.

Gyllenhaal confirmed for Letterman that "65 percent of the movie we don't have our clothes on — or according to you, only she doesn't have her clothes on." But filming sex scenes isn't sexy: it's a complicated procedure. "It's very much like football," he said. "There are plays and you gotta look for holes in her defensive end. It's just the truth of the art form." –AMY LEE

Watch the interview below:

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