I happened to stroll through one of your larger stores at lunchtime today. What a mausoleum to misplaced hopes is Marks & Spencer at Christmas time] What tiny bedtime tragedies are presaged by the ranks and rows and swags and festoons of glossy, lacy, teeny-weeny underwear]

I should like to see notices prominently displaced in your lingerie sections: something along the lines of 'Smoking may damage your health', only these would say 'SATIN AND LACE CANNOT REPLACE YOUR SEX LIFE'.

Men are encouraged to believe that the giving and wearing of minute scraps of exorbitantly priced underclothes is the prelude to a night (or, who knows, a morning, an afternoon, a lunchbreak most likely) of rampant, uncontrollable, Fatal Attraction-type sex. This profitable misapprehension sees its finest flowering at Christmas, as Marks & Sparkses the length and breadth of the country prove.

The problem is threefold. One: real wives, partners, paramours or girlfriends are almost certainly not the anorexic Miss Whippet of the lingerie advertisements, but are blessed with the standard arrangement of bulges, bumps, lumps and other forms of female shapeliness. This means that whatever is bought for them will be too small, and on Christmas morning they will have the humiliation of saying so. So if men must buy 'frillies' or 'scanties' or whatever the nasty itchy little things are called, your sales assistants should be instructed to tell them that if they haven't ascertained the right size they must go back and ask. Alternatively, they should be told to think of a size and double it. 'She's about as big as you', accompanied by undulating movements of the hands, won't do.

Second disillusionment: underwear, even if it fits correctly, looks good only once. While it's all shiny and slinky and straight out of its Christmas wrapping paper it can seem quite enticing. Once it's been through the washing machine (along, no doubt, with a football shirt, cheap blue socks that run, and the scarlet Y-fronts that she bought as an act of revenge), it loses that pristine colour and texture and takes on a wrinkled greyness, with droopy bits of tired lace, that is most unappealing.

You know this, Sir Richard, and so do your sales assistants but you never tell the male customers. So the poor saps spend heaven knows how much to match up the woman of their fantasies with the woman in their double bed and it's doomed, doomed, doomed.

Here we come to the third and saddest problem of all. You know quite well - I dare say you've even done it yourself - that men buy underwear because it makes them feel sexy. They naturally conclude that it makes women feel sexy, too. This masculine belief that a droopy, sagging sex life can be perked up by the wearing of something small and triangular in crimson satin with black lace edging is one of the most poignantly optimistic, recurring myths of our time. But myth it is.

Good sex takes place between consenting, naked adults. It has nothing to do with lingerie. Marks and Spencer makes a fortune, especially at Christmas, by pretending otherwise. Shame on you, Sir Richard]

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