Why more chicks are now cheating: if you're itching to step out on your man, .you're one of many. Here's what's driving temptation these days ... and how to resist it.(COSMO NEWS: Relationships)

The latest figures are out from a survey of American behavior: 15 percent of women under 35 say they've cheated on their spouse. And that's just the tip of the infidelity iceberg. "Women underreport 'affairs in face-to-face studies, so real numbers are likely three times higher," says David C. Atkins, PhD, a University of Washington research associate professor who evaluated the stats.

Something is clearly spurring this desire, and many experts chalk it up to a seismic shift in our view of sex. "Women feel entitled to pleasure, so going outside the relationship is no longer taboo if it satisfies needs a partner isn't meeting," says M. Gary Neuman, author of The Truth About Cheating. Factor in the ubiquity of "starter marriages," celebs who stray with impunity (Brangelina, anyone?), and sites like ashleymadison.com that engineer extramarital affairs and before long, the idea of lifelong monogamy seems quaint at best.

Compounding that license to cheat is a whole new world of enticement. Today, women kick more ass than ever at work. But that demands time at the office and on the road, rife with temptations like a work "spouse" or cute guy at the hotel bar. "Business trips and spending less time with a partner are related to the higher likelihood of an affair," says Atkins. Even at home, you have access to anybody and everybody online, That guy who got away? He's at your fingertips on Facebook. And technology makes it easier ...