If ''Kate'', Fairfax's Woman of the Year, had filmed her sexual encounter with a male army cadet and spread it around the internet, do you think he would have felt humiliated? Would he have been hounded from the military? Would he now be saying, ''It was three years of my life, massive systemic hostility and a ruined career but it was worth it''? Hardly. He would have bought the next round of drinks and had a laugh. No recovery required. Nothing to pay. Sex, for boys, is still usually costless. This is social attitude, yes. But it's not just that. It's also about how the genders see and value sex. As a male friend put it recently, ''Men want love for sex, and women want sex for love.'' I believe this is broadly true. It's biological. Contradicting the usual thought-pattern diagram, girls are very focused. There's a level at which most girls want one nest, one litter, and one good bloke to guard it. At that same level, men want to be Genghis Khan, spreading their seed over the steppes. Until we recognise this difference, and honour it, supposed sexual revolutions will always favour men. That happened in the '60s. The pill suddenly freed women to have sex when they chose. But it also meant they were much, much easier to pressure into it when they didn't, really. Arcing from feminism to fecundity, women began by burning bras in the streets, and ended up making yoghurt and bean sprouts in the kitchen. For men, traditional sexual prohibitions - medical, reproductive, moral - were merely a hindrance, so their removal was wholly welcome. For women it was, as ever, more complicated. The strictures had always been both a hindrance and a refuge, so their removal was a mixed blessing.

Flower power expected that women could, would and wanted to make love with everyone, all the time. Like men. But in truth, although some women wanted this, most did not. Social pressure not to be ''square'' was intense, but you couldn't talk about it. Social pressure had been specifically jettisoned, so how could it even exist? This sounds absurd. It sounds like Tess of the d'Urbervilles or Jane Eyre - until you realise the situation now is astonishingly similar. We like to think the current young-adult population has sexual politics, if not gender politics, sorted. But news from the front suggests otherwise. Today's twentysomethings consider it normal that, as one young woman told me recently, ''all guys watch porn''. In the dating scene, ''sex first, talk later'' is standard policy and you don't take offence if a boy says sure, he likes you, but just wants to be your f--- buddy. Personally, I don't care how promiscuous people are (although if someone had tried the f-buddy line on me, or popped off to a porn flick, you wouldn't have seen me for dust).

To me, promiscuity is not a moral issue, as long as it's what both - or all - parties want. Certainly, women's behaviour has started to suggest a shift from quarry to hunter. We've all seen the groups of clearly predatory young women prowling the wee-hour streets in their total-exposure skirts and heels you can tolerate only if you're blotto. But what's more difficult to judge is how far women feel pressured into this behaviour, just as they are injection-moulded into the clothes. I've tried. I've had whores explain to me that, for them, prostitution is a feminist statement. It's about them taking control. I just can't buy it. It seems to me no accident that Rachelle Louise, Simon Gittany's girlfriend, wore massive platform stilettos to court every day. These shoes symbolise bondage. Watch any girl hobble down Oxford Street in 10-inch heels and tell me it's not a form of foot binding. So the question is, to what extent has it become obligatory for women to evince not just sexual appetite but male-pattern sexual appetite; spreading it around with minimum emotional engagement?

You hear tales. Such as the one about the girl who'd been sleeping with a guy for several weeks before it was OK to wonder, even to her friends, ''How can I ask him if we're actually going out together? Can I do it by text?'' Then, suddenly, you're 35 with an empty nest and a ticking biological clock. Is this liberation? Or is it bondage, redoubled? Of course, it's different when the protagonists are children. This is partly because at 14 they're not children. In Shakespeare's time, they would have been marriageable. And partly because it's not about what they want. It's about what we want for them. One thing we, as a society, have decided we want is artificial childhood extension. Longer childhood allows education, and lets children's judgment centres catch up with their glands. This is arbitrary, except that childhood length is directly proportional to every standard of civilisation. They'll have better lives, and be better citizens. So we must recognise the abiding truths. Yes, sex means more than a handshake. Yes, this is truer for girls than for boys. Yes, it comes down to control: in the case of children, parental control. Someone has to be the bitch. Probably you.