And yet sexual advice has fashions, just like clothes. If you'd written to an agony aunt about your husband's impotence 30 years ago she would either have advised you to thank your lucky stars or suggested you buy some feminine nighties to arouse him. Later came the idea of spontaneous sex - in the kitchen, in the study, on the floor, in public. Next, the pendulum swung to making dates for sex so that you could build up to the idea of sex; the less spontaneous the better, in other words. At one time sharing staring at pornographic magazines was the answer, the next minute pornography was thought a very bad idea since it usually made women jealous and upset and gave both partners incredibly unrealistic ideas about what good sex was like. Then there was enacting your fantasies. Then there was another great piece of advice, zen-like in its artifice. In order to have good sex, hey, why not have no sex? Couples were encouraged to lie and stroke each other for ages without having any genital contact at all. Thrilling.
The truth is that when you've been together for ages sex just isn't as mind-bogglingly exciting as it was when you first met. If you want fantastic sex again you'll have to get a new lover. You can, of course, recreate the buzz of having someone new by simply fantasising you're having sex with someone new. Your partner need never know, and anyway may have been fantasising about someone else for ages. Or you can console yourself with the fact that sex may not be thrilling any more but has a certain quality of its own, a kind of friendly, leisurely certainty about it. It's never going to be as great as it was, but it's never going to be frustrating or disastrous.
But for those couples whose lives in bed have become unutterably stale and who have tried all the usual suggestions, and for whom a dinner bathed in candlelight, drenched in gypsy bands, and consisting entirely of celery and oysters or whatever it is that's meant to act as an aphrodisiac, bodes not so much a night of lust but a night of being violently sick after a dud shellfish, I can offer only one piece of advice which I have never suggested nor seen recommended before. Why not have a day's silence before having sex? Communicating by notes, or gestures, is like meeting someone new, and writing notes is a new language: you have to make yourself particularly conscious of each other's needs, and making yourself clear involves a lot of touching, as well. All this, in theory, should heighten your physical closeness and awareness of each other and make sex better. And if anyone is game enough to give this a whirl, then I'd be glad of the feedback. I might even try it myself.