Maggie Gallagher

Mark Regnerus, a sociology professor at the University of Texas in Austin and the author of "Premarital Sex in America," pointed out something no woman likes to hear.

For women, he said, infidelity tends to happen when they are unhappily married. But even many happily married men will regularly engage in this type of behavior, to the great consternation and surprise of women.

I emailed professor Regnerus for comment. He made a point of telling me he does not believe Anthony Weiner should resign.

"These things never surprise me," he said. "The male libido can be a very unstable thing, a mystery even to the self, and certainly to women. Men's sexual 'memory' tends to be very short. ... As a result, men don't seem to learn much from their fellow men's public blunders."

Sexual memory?

"When the libido kicks in, what happened in the past seems to them largely erased, and they're primed for opportunities in front of them," he said. Men with a very strong moral compass may resist temptation, but temptation they will have. "Men have plenty of free-floating desire," he told me, "and it's not often very discriminating."

He pointed me to a quote in Steven Rhoads' book "Taking Sex Differences Seriously":

"The libidos of perfectly ordinary men, when fully understood by women, seem deformed or disreputable to them. Many women strongly resist an accurate presentation of male sexuality."

Yes, it's the indiscriminate quality of lust that appears deformed to most women, probably because it contradicts our own cherished sexual fantasy of being the chosen princess -- the object worthy of all desire.

Huma Abedin is Anthony Weiner's beloved princess. He seems to genuinely feel that way about his wife. But that doesn't mean Weiner would not like Meagan Broussard to admire his ... underwear.

Sad, sordid, stupid.

How can sex scandals manage to shock us over and over again?

Part of the answer for women, Regnerus suggests, is that we are socialized to believe gender is irrelevant, which tends to make us blind and sometimes dumb.

As for men, I'll leave the last word to Regnerus: "What men are having trouble understanding is the permanence of the digital record. One foolish tweet outlives all the many one-to-one sexualized comments that never get recorded."

Welcome to the Facebook generation in politics.

Maggie Gallagher

Maggie Gallagher is a nationally syndicated columnist, a leading voice in the new marriage movement and co-author of The Case for Marriage: Why Married People Are Happier, Healthier, and Better Off Financially.