Whatever happened to wifely duty? Any thought that sex should still be included in the list of obligations that come with tying the knot is likely to be greeted with a hoot of derision by women today.
Wives willingly embrace far more tedious demonstrations of devotion like searching shopping centres for his favourite Y-fronts, to say nothing of bearing and raising his sprogs. But as for having a quick romp in the sack when they aren't quite in the mood that's beyond the pale.
These days unless women want sex it just doesn't happen. Women's right to say no has been enshrined in our cultural history since the 1960s when women's sexual rights became a rallying cry. As terrible stories of marital rape and sexual violence claimed the public's attention, women's right to refuse sex became fundamental to decent relations between the genders.
The new rule was that sex must wait until women are well and truly in the mood. But that was where we went wrong. The assumption that women need to want sex to enjoy it has proved a really damaging sexual idea, one that has wrought havoc in relationships for the past 40 years.
The problem is that in long-term relationships men are far more likely to retain their sexual drive than their partners. The No1 sexual problem plaguing women is low libido which means couples everywhere are struggling with a mismatch in desire. Women lie in bed worrying the hand will come creeping over. Men spend their lives grovelling for sexual favours. The gap between them in bed becomes a chasm.
This night-time drama is the source of great tension and unhappiness. Last year I recruited 98 ordinary couples to keep diaries recording their intimate negotiations over sex. The most powerful responses came from men, as their frustration pour out in a howl of disappointment and anger.
Many reported feeling duped, stunned that their needs are so totally ignored. But they rarely publicly voice these concerns. In the early 1960s, Betty Friedan wrote in The Feminine Mystique about ''the problem that has no name'' women's unvoiced frustrations with their housewifely role. Women live unexamined lives, she said and encouraged women to say, ''I want something more''. We have been saying it, very loudly, ever since. But now it is men who live unexamined lives, keeping their hidden yearnings to themselves. Their ''problem that has no name'' is sexual frustration.
Yet their problem has a solution. It is quite possible for women and indeed for men to enjoy sex without desire. Research by Professor Rosemary Basson from British Columbia has shown many people can experience arousal and orgasm without prior desire. She explains that provided there's a willingness to be receptive, the rest follows.
Once the canoe is in the water, everyone starts happily paddling. For couples to experience regular, pleasurable sex and sustain loving relationships women must get over that ideological roadblock of assumptions about desire and ''just do it''. The result will be both men and women will enjoy more, better sex.
The alternative is the status quo namely that the low-drive partner, usually the woman, controls the couple's sexual frequency and meters out sexual favours only when it suits her. This leaves the man in the degrading situation of having to beg for sex, keeping her happy in the vague hope of getting some. But is that so different from the much maligned husband who controls the family purse strings, doling out pocket money to the little woman if and when it suits him?
Last year the Victorian Government introduced laws targeting men who commit ''domestic violence'' by financially controlling their partners. Surely restricting or cutting off the sex supply in a monogamous marriage is no less abusive. Why don't we ever talk about the fact that a monogamous relationship must imply mutual commitment to satisfying each other's sexual needs?
But of course it works both ways. There are couples where the man is simply not interested. Here too, there is an obligation to just do it. Not so easy, some would suggest, pointing to the more obvious links between desire and male performance. Yet there are many ways of pleasuring a woman which place no demands on the man's equipment.
That's a message that older men need to take to heart. I had very unhappy older female diarists whose partners retreated into grumpy isolation at the first sign of erectile failure.
Yes, that's a mighty loss for a man but a considerate man will still strive to maintain physical intimacy.
The issue is not just sex, not getting rocks off but the emotional experience of making love, feeling connected, wanted and desirable and not facing the humiliation of constant rejection. It's an issue that cuts to the heart of a real relationship.
Bettina Arndt's book The Sex Diaries is published by MUP. She will be speaking at the National Press Club today at the book's launch.