Jake Gyllenhaal on David LettermanDavid Letterman enjoyed Jake Gyllenhaal's new movie, 'Love and Other Drugs,' but found it quite shocking too. There's a lot of nudity. And it's a kind of nudity the host didn't expect, he told Gyllenhaal on 'Late Show.'

He stuttered as he tried to explain, "You get excited when you first, you see [Anne Hathaway] -- uh, she starts, she is undressed ... 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 responded sarcastically, "Usually, when people have sex -- whatever, intercourse -- both people have to take their clothes off, David." Letterman said, "I know, but for some reason I didn't see that coming." The actor told the audience 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."