For most people in relationships, a commitment means no playing around, ever. That doesn’t mean there aren’t plenty of love rats out there.

About one in five adults in monogamous relationships, or 22 percent, have cheated on their current partner. The rate is even higher among married men. And nearly half of people admit to being unfaithful at some point in their lives, according to the results of the MSNBC.com/iVillage Lust, Love & Loyalty survey.

More than 70,000 adults completed the online reader survey in February, answering about 30 questions that revealed their intimate feelings about adultery and what makes them stray or stay faithful.