I'm a 34-year-old woman, and I've been with my boyfriend for three years. I've noticed a weird pattern. Guys looking for a fling get MORE interested instead of less when I tell them I'm in a relationship. I don't understand. Even if I were willing to step out on my boyfriend (which I'm not), why would any guy want a cheater?

--Committed

You're saying: "I have a boyfriend. Get lost." They're hearing: "Cool! I can get sex without the crying, the tampon runs, and the map on the nightstand for the precise placement of each of the 300 throw pillows."

Evolutionary researchers Susan M. Hughes and Marissa Harrison found that women in committed relationships (compared with men) were more likely to reveal their relationship status to a potential hookup partner. They speculate that it "may appeal to a man's evolved psychological preference for short-term mating, which increases his chance of reproduction without commitment."

Of course, men these days aren't consciously looking for "reproduction" with their hookup, but birth control is "evolutionarily novel." In other words, the psychological operating system that's driving all of us today is, shall we say, old-school. It evolved to solve ancestral mating and survival problems, so it's sometimes a bit mismatched with the world we live in today. For example, our genes operate on the principle that having sex -- whether it's relationship sex or hit-it-and-quit-it sex -- leads to reproduction, not really nice dividends for stockholders of condom companies.

Again, a guy in hookup mode isn't reflecting on these psychological underpinnings. As he sees it, he gets all of the sexytime fun but nobody hands him the usual bill...which is to say there are jobs women give their lover -- "Get naked!" -- and jobs they give their boyfriend: "Get into this 'Proud Cat Daddy' T-shirt!"