About three-quarters of the survey takers say they've made a monogamous commitment, with a majority either married or remarried.But a significant portion found it easier to make that promise than keep it.
"It is surprising that the wives and husbands and girlfriends aren't more suspicious," says Lever.
"Even when they know something's amiss — a sex life that's fizzled or intimacy waning — they count on their partner's love to keep them from straying." Philanderers are so inscrutable partly because there’s no single profile for a cheater.
The study found that 22 percent of married men and 15 percent of married women have cheated at least once — similar to the results from the MSNBC.com/i Village survey.
Still, much of this depends on your definition of cheating.
The new lover is most often a friend or co-worker, and the typical fling lasts less than a week.