A friend of mine once called me to complain that she was driving her husband crazy because she was not interested in sex. At the time, her first child was very small. I thought about her situation (and mine, frankly) and said, "Well, I know what your problem is. It's the theory of butts."
And then I explained how the butt theory affects many young women in the throes of raising wee ones. "The deal is," I continued, "you get up in the morning and change your child's little butt, and then you feed him and have to change that little butt again. You often have to deal with explosive movements out of that butt, rashes, gas, et cetera. And your entire day revolves around nurturing that baby and dealing with his butt. At the end of the day, the last naked butt you feel like seeing is your husband's." When my girlfriend stopped laughing she said no one had explained things like this to her quite that way before. You can't argue with genius.
I often think the sex drive difference between the genders is absolutely cruel. Men are jacked up--testosterone is like gasoline cruising their veins and they don't need anything stronger than the sight of a woman in a thin sundress to raise their flag. Women's sex drive is different. It's not the same release as men. Our situation has to be right. Once we marry and start service mode (cleaning toilets, yelling at you because you eat cholesterol instead of fiber, managing the odd and semi-controllable on-goings of children), sex can feel like an extension of service.
My children are getting older, so really the butt theory doesn't apply to me very much anymore. They go to bed and stay there at night, for one thing. And my husband has figured out how to make things work to his advantage when I might be in an otherwise non-pliant mood. (Let's just say we have no problems in that delightful area of our relationship.) As for butts now, I often joke with my son that he needs to take off his clothes for a bath because "you know how much I love a naked man." Tiny laughs and laughs at this. Of course, one day, I won't be able to say this anymore without him responding, "Ew, gross, Mom. Cut it out." But by that time, I really won't want to see his butt, either.