The relationship is hanging on by a thread; the prospects don't look good. When David called Frances in Wisconsin recently, she told him she was on her way to help a friend "feed the chickens."

"But I found out later she was really going over to fuck this other guy," David says. Which, it seems, is an elevated risk these days if your partner is not getting what she needs in bed—and on the kitchen counter and the bathroom linoleum.

"We're now in the post-Samantha age of the milf," Kerner notes, alluding to the Sex and the City cougar.

For some guys, that will mean more sex than they ever imagined. For others, it might be time to find a younger girlfriend.

Bring Sexy Back
Six ways to boost your libido

Pump iron or watch an action movie. Testosterone surges following tough-guy activities.

Talk about your feelings. Your sex drive is tied to your state of mind. If you're nervous or stressed, clear your head by speaking.

Eat fish. It's full of zinc and phosphorous, both of which are known to increase testosterone levels.

Think about booze. Researchers at the University of Missouri-Columbia found that exposure to words like beer and keg can affect men's interest in sex.

Lose your gut. Fat cells suck up a certain amount of testosterone, but the ones in the stomach do it most efficiently.

Stay away from meds. Yes, anti-depressants dampen your libido, but so do over-the-counter pills with the warning "May cause drowsiness."

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