Along with qualities like “devoted,” “adventurous,” “successful,” and “cute,” the checklist of women deciding what they want in a man may now include “the fidelity gene.”

A study by a behavioral geneticist at the Karolinska Institute in Stockhom confirmed what we already knew — when it comes to monogamy, it’s not about us, it’s about them.

Some guys, well, can't help themselves. You can blame the genes when he can't keep it in his jeans.

The gene in question controls the number and location of vasopressin receptors in the brain. Vasopressin is a hormone secreted during sexual activity that increases the likelihood of pair bonding.

One allele, or alternate form of a gene, and there are fewer vasopressin receptors. Two alleles and there are way fewer vasopressin receptors.

As The Washington Post reported, the finding is striking because it not only links the gene variant — present in two out of five men — with the risk of marital discord and divorce, but also appears to predict whether women involved with these men say their partners are emotionally close and available, or distant and disagreeable.

The presence of the allele also seems predictive of whether men get married or live with women without getting married.

"Men with two copies of the allele had twice the risk of experiencing marital dysfunction, with a threat of divorce during the last year, compared to men carrying one or no copies," said Hasse Walum, a behavioral geneticist at the Karolinska Institute in Stockholm, who led the study. "Women married to men with one or two copies of the allele scored lower on average on how satisfied they were with the relationship compared to women married to men with no copies."

The scientists studied men because vasopressin plays a larger role in their brains than in women's brains.

So does this mean that along with a pre-nup you should ask your intended to get a DNA test? Will men like Bill Clinton, Eliot Spitzer, and a conga line of lotharios then be given yet another excuse for bad behavior?

“Nothing personal dear, it’s in my genes.”

Naturally, these findings are already sparking debates and late night jokes.

The scientists were quick to point out that this allele is a factor that “increased” the risk but it could be controlled and that other issues impact fidelity. And those include religion, family background and desire — as in desire not to cheat.

"There are many ways this information can help a man and his wife when they marry," Helen Fisher, a biological anthropologist at Rutgers University who studies romantic love, told The Washington Post. "Knowing there are biological weak links can help you overcome them."

A man who knows he has this allele, she added, might be able to use the knowledge to ignore tugs of restlessness he might feel in his marriage: "You can say, 'Oh, it is just my DNA, and I am going to ignore it.'"

On the other hand, if you're a divorced woman with some bad experiences, you may think that DNA now stands for Date No one with Allele.