Anyone who thinks it's mostly men who commit adultery is in for a wake-up call. Researchers now say women -- particularly younger ones -- are on par with men when it comes to seeking greener carnal pastures.

A University of Washington study found that about 15 percent of women under 35 had been unfaithful, up from 12 percent in 1991. (In the new study, 20 percent of men had strayed.) And the lifetime rate of infidelity for women over 60 rose from 5 percent to 15 percent in the same time span, while the numbers for older men went from 20 to 28 percent.

But researchers are scratching their heads over whether it's really more women cheating or just more coming clean about it. Scientists say it's tough to get women to admit to adultery -- a study published last year in The Journal of Family Psychology found that only 1 percent of 4,884 married women said they had been unfaithful during a face-to-face interview, while 6 percent admitted it on an anonymous computer questionnaire.

If more ladies really are unleashing their libidos elsewhere, researchers theorize that the cause could be everything from having careers that require them to work late hours to being able to connect with people electronically. Don't forget -- back in the 1950s when there was less cheating reported among women, most wives stayed home, which diminished their opportunities to seek out other partners.

Other factors leading to increased infidelity among women? The increasing frequency of sexless marriages, even among celebrity couples (whither Madonna and Guy Ritchie?), and the breakdown of stereotypes that women with multiple partners are slutty while mate-juggling men are studs (thank you, "Sex and the City"). Or maybe it's just the prevalence of one of these Top 10 Reasons Women Cheat.

Tell us: Have you ever cheated?

Also on Lemondrop: Check out this gallery of celebrity hotties who suffer from disorders such as wandering eyes.


Hot Bod Cold Heart

    Mario Lopez Who knew that A.C. Slater was such a dirtbag? The buff "Dancing with the Stars" stud reportedly cheated on one ex-girlfriend with a Hooters girl, and his two-week marriage to Ali Landry ended when she learned of his bachelor party antics.

    Barry King, WireImage.com

    Jude Law He may be gorgeous (and who can resist that accent?) but not so hot was his cheating on then-fiancee Sienna Miller with the nanny to his kids. Miller and Law eventually broke up, and her downward rebound spiral led her into the arms of mangy Rhys Ifans.

    Sony

    Matt Damon Although he has denied it, Minnie Driver says she discovered she was dumped by watching "Oprah. Say what!? The "Sexiest Man Alive" told the talk show host he was no longer dating Driver; Driver claims it was the first she'd heard of their breakup.

    Universal

    Hugh Grant Who could forget the Hugh Grant scandal that rocked Hollywood in 1995? Grant was pulled over by LA police for lewd conduct with prostitute Divine Brown. Girlfriend Liz Hurley forgave him and even appeared on his arm at the premiere of "Nine Months" days after his arrest.

    Dave Hogan, Getty Images

    David Beckham What is it with married celebrities and the hired help? Although he has always denied it (and ok, so there's no proof), Becks was accused in 2004 of sleeping with then-personal assistant Rebecca Loos.

    Milk Processor's of America

    Chace Crawford We know two things about the "Gossip Girl" boy: He's a total hottie, and he dumped Carrie Underwood via text. US Weekly reported in April 2008 that the pair "mutually" parted ways via cellular phones.

    Mark Von Holden, WireImage.com

    Charlie Sheen Among other lowlights, Sheen 'accidentally' shot ex-fiancee Kelly Preston, spent thousands on madam Heidi Fleiss, and symbolically took a chainsaw to his wedding portrait with Denise Richards. Ew.

    E.J. Camp / CBS

    Ethan Hawke We were sad enough when this brainy babe's artsy-smartsy marriage to Uma Thurman ended. But to then shack up and have a baby with the nanny to his kids with the hot blonde? For shame!

    Mirimax / Everett Collection

    Ryan PhilippeAlthough never officially confirmed, rumors still swirl that Ryan Philippe's divorce from his all-American wife Reese Witherspoon had a little something to do with an on-set affair with actress Abbie Cornish, now his girlfriend. Hmm.

    Frank Masi, Paramount

    MC Harvey This UK recording artist was caught in the act with his wife's good friend. Who caught them? The other woman's then-boyfriend. Now that's some drama, folks.

    Stuart Wilson, Getty Images