Maggie Gyllenhaal asks 'Why is sex fun?' for Discovery channel

CURIOSITY continues with WHY IS SEX FUN? Sunday, August 21, 2011 at 8PM e/p on Discovery. | In this Curiosity video we follow Maggie Gyllenhaal in exploring how female brain activity changes as a woman reaches orgasm.

The Gyllenhaal siblings sure like their Discovery Channel!

First Jake Gyllenhaal joins Bear Grylls for "Man vs. Wild" and now Maggie Gyllenhaal hosts the third episode of the first season of "Curiosity."

In her episode, which aired Sunday, Aug. 21, Gyllenhaal hosted a revealing investigation into the latest scientific research on orgasms and sexual pleasure. The press release says, "Sexual pleasure is among the most prized, meaningful and richest experiences known to man. But the orgasm is a true scientific puzzle."

Maggie sits with Selma Blair, Claire Danes and Parker Posey

There's a clip above of Maggie's episode and if you missed its first broadcast, it re-airs on Discovery Sunday, Aug. 28 at 11 a.m. ET, Monday, Aug. 29 at 8 p.m. ET and 11 p.m. ET and Wednesday, Aug. 31 at 3 a.m. ET Source: