"Despite stresses and chores, the male sex drive usually stays intact because men have 10 times more testosterone," she explains. "The human female's sex drive is less innate and therefore more vulnerable to stress."

So, if you don't schedule time for between-the-sheets meetings, you're setting sail on a sexual rut that stretches way beyond tonight's anticlimax. Now this doesn't mean you should force your tired self into sexy lingerie and seductress mode. According to Sapire, new research has shown that women are generally sexually neutral creatures – meaning that unlike men, they're unlikely to feel randomly randy while walking down the street or doing the dishes.

"Women think they're freaks if they don't feel a baseline desire for sex," says Sapire, "but it's normal not to feel it after a long day of chores. So stop waiting for desire. Change your attitude to simply making yourself receptive to your partner's stimulation."

Try this: when the dishes are dried and the kids asleep, light a candle, lie in a bath, read erotic material and tune in to what turns you on. "Once a woman tunes in to stimulation from her partner, she'll feel aroused," says Sapire. "And then the desire comes, because arousal stimulates the desire for more."

So, what starts with a little time, and a shift of focus, becomes an effortless sense of desire that sweeps you up, up and away. Let go. Let it happen.

Is life getting in the way of great sex? Tell us in the comment box below.