The sports world’s golden boy, Tiger Woods, isn’t looking so golden any more. We’re all glued to the story as details emerge about mistresses, sexting, and incriminating voicemails. Of course, David Letterman and ESPN’s Steve Phillips were the last crop of cheating men to dominate the headlines. And while the media has a field day with it all, the idea itself that men cheat isn’t exactly new.

According to the 2004 American Sex Survey, the sad truth is that almost one-fifth of married or co-habitating men will cheat on their partners at some point in their relationships, and while it may be easy to throw your hands in the air and proclaim that all men are ruled by their penises (after all, how else can you explain two men dumb enough to cheat on Halle Berry and Christie Brinkley?), more often than not, what leads men to stray isn’t just about sex.

According to Dr. Scott Haltzman, a Brown University professor and psychiatrist who specializes in gender issues, men cheat as a result of three factors: need, opportunity, and the inability to resist impulses.

Read Tiger Woods: The Fairytale Is Over

“Most people assume that men cheat because they need or want more sex, but excluding the maybe 20 percent of cheaters who are sex addicts, there are usually more complex psychological issues at work.”

That certainly seems to be the case for Rick*, 46, who confesses that although he has been married for 19 years, he sees escorts on a regular basis to boost his self-esteem.

“My spouse over the years has stopped liking sex that I like. I do my best to please her, but it goes both ways. On some level, I cheat because of personal insecurity about myself and my ‘manliness’ and attractiveness. For an hour or so, I am a handsome, desirable man who is good in bed and still has the ability to please a woman in many ways (although I will admit pleasure can be real and can be faked). That's satisfying on many levels,” he says.