Later today the luminary authorities who run the magazine The Literary Review will — for the 15th time — announce the winner of the Bad Sex in Fiction Award. The original object of this prize was to “draw attention to the crude, tasteless, often perfunctory use of redundant passages of sexual description in the modern novel, and to discourage it”. Clearly this is a long-term project because, as I write, those who are threatened with receiving the unwanted gong in front of a sniggering audience include the novelists Iain Banks, Norman Mailer, Ali Smith and Jeanette Winterson, as well as Ian McEwan for his detailed descriptions of various low-key sexual fumblings in On Chesil Beach.

Allow me now to draw a line of connection — one that is going to seem tenuous. Just last Friday the Health Protection Agency reported on an important aspect of non-fictional sex. This was that, in 2006, the number of sexually transmitted infections (or STIs) rose to 620,000, up by 2.4 per cent on the previous year. It estimated that 73,000 people in Britain live with HIV, one third of whom are unaware that they even have the virus. Nor is this, as some like to imagine, about African migrants; among gay men there were 2,700 new diagnoses of HIV in 2007. Naturally, young adults accounted for a high level of infections, including genital warts (the virus for which is linked to cervical cancer), gonorrhoea and chlamydia.

It's possible, of course, that the greater effort put into screening is partly responsible for the year-on-year rise. Even if this is the case, we are still left pondering a British paradox: how does it come about that there is so much sex in the culture and yet so little knowledge of how to prevent oneself getting or passing on this life-threatening virus or that unpleasant germ? Since this is my column, I will dispense peremptorily with the eternal lobby that links disease with “too much” sex education and argues that if we knew even less about sex, then we'd be less likely to do it so often. They would not apply such logic to any other realm of human existence.

Leaving them behind, could there be another explanation, which is that the problem lies partly in our cultural attitude to sex? One represented, at an elite level, by The Literary Review's own otiose award? A warning: here, to illustrate my argument, I must provide some examples. In 2001 the judges shortlisted a book called Rescue Me, by Christopher Hart. One passage read like this: “Her hand is moving away from my knee and heading north. Heading unnervingly and with a steely will towards the pole. And, like Sir Ranulph Fiennes, Pamela will not easily be discouraged.” Last year Will Self's The Book of Dave was cited for a passage in which the eponymous taxi driver “approached Michelle as he would call over a run: leave on left tit, comply throat, comply mouth, left shoulder, right hip, forward c*** ... The junctions of her body were well signed, and his Knowledge was sufficient to hold her.”

After reading those extracts I wasn't surprised when the deputy editor of The Literary Review admitted that, at the awards ceremony, “the passages that get the biggest laughs are not always those that qualify best for the award”. Because I think both the two above examples are of writing about sex that is actually rather good, rather funny and rather true.

In 2004 the sex in a Tom Wolfe novel was described by the judges as not just “ghastly” and “inept” but “unrealistic”. That word “unrealistic” took me back to the recent story concerning the man who was caught copulating with his bicycle. It was the first such case in the courts, we were told, since 1994 when a Redditch man was fined for having sex with a pavement. Such is human complexity and ingenuity, there isn't any kind of physically plausible sex that you can dismiss as “unrealistic”.

But what motivates an award for “bad sex” writing, and nor for any other category? Why not the dreadful dialogue award? The Dan Brown Award for ludicrous character names? Or (and this would have a legion of nominees), the “most inept allusion to the war in Iraq on an arts programme” award? Once again the The Literary Review's deputy editor inadvertently explains the reason. “In general,” he wrote, “‘good' sex in novels is neither seen nor heard; the eroticism comes from what takes place outside the bedroom. The deed of darkness itself usually provides little but pornographic interest.”

McEwan's book proves the man to be wrong a hundred times over. There isn't a word in On Chesil Beach that is gratuitous or unnecessary to the story of how love is nothing without kindness. The Literary Review's award, and its lionising by the media world, is about embarrassment, not aesthetics. It is a way of talking about rumpy-pumpy and houghmagandy, about expressing a prurient interest in sex, without ever admitting that you are serious about it.

The “deed of darkness”! It is a way of thinking in which the elite allow themselves to be ironic about sexuality, without confronting its reality, while popular culture (run by the same elite) in the form of television programmes and magazines, will tell a teenager how to give her boyfriend a blowjob, but not that hepatitis C can be transmitted in this way. Sex is reduced to “sessions” and “romps”; it isn't engaged upon for enjoyment or pleasure, but for social advancement or to keep your girl or man from straying. And whatever you do, don't seek to write seriously or truthfully about it, because that just invites the appearance of that most heavy-handed of thought policemen, Officer Ridicule.

For some reason we Brits (or is it just the English) have more difficulty than most in living with our own ambivalence, which is that light and dark and bad and good co-exist in the same bodies and minds. Everything for us has to be either/or, or else suppressed. Perhaps that's why it took me years to understand a Yeats poem I learnt at school. Titled Crazy Jane Talks with the Bishop, the verse has an anti-heroine reproving a sanctimonious prelate when he entreats her to renounce her physical self.

A woman can be proud and stiff

When on love intent;

But Love has pitched his mansion in

The place of excrement;

For nothing can be sole or whole

That has not been rent.

I understand it now, even though it would probably win the Bad Sex Poem Award at The Frightfully Clever Club.

Times Recommends

• Police beg us for food. What hope is there?
• Moral darkness that engulfed Baby P
• More to Advent than cheap chocolate