I STOOD, dressed only in my best grey socks, watching the two lithe 21-year-olds gyrate in a lewd and libidinous manner before me.

Then, momentarily, my vision cleared and I realised that, in truth, there was only one of them and that I'd had more to drink than I thought. She did have two chins, right enough. Also, if she was 21, then the Suez Crisis must have occurred last week.

I tried to think: "What would Sir Anthony Eden do in a situation like this? Did he ever have sex? Or did he get his butler to do it for him?"

Looking down in the direction of my honourable member, I saw that nothing stirred. Would that it were the same in other hind quarters. After eight pints of gassy beer and a kebab, my bottom was desperate to blow a raspberry.

However, I knew from bitter experience (ie waking up in casualty), that women do not care for this sort of thing during mating - if that's the word for which I'm desperately groping - and so prepared myself for the worst.

And that, ladies and gentlemen, is how to write a sex scene. The curtain falls after the word "worst", and the act of coitus is left where it is always best performed: in the imagination.

Other top literary writers - ken? - make the mistake of going too much into the nitty and, in some particularly x-rated cases, the gritty. What's the point? It adds nothing to the plot. You might as well spend five pages describing how the hero flossed his teeth or fixed the door on his garden shed.

Actually, the latter has given me an idea for a novel ("Frankenshed") but, in the meantime, we remove the bridie-crumbs from our cravat and note with asperity that Scotland's leading literary broadcaster has been nominated for this year's bad sex in fiction prize.

Yup, Kirsty Wark - the People's Kirsty, star of Newsnight and posh artsy stuff on BBC2 - has been found wanting in the literary bedroom. I will not trouble you too much with the lascivious details. Apart from that woman at the back with the false beard, we are all men of the world here and have had sex at least once.

Accordingly, we recognise Kirsty's allusions to undone buttons, cupped breasts, arched bodies and so forth. I cannot think, however, why a tongue is brought into proceedings. Indeed, there is one disturbing description of "licking beads of perspiration from my skin".

To be fair, in the unjust sense of the word, there is a moving bit at the end, where the heroine gasps: "I had never imagined I was capable of wanton behaviour."

Hitherto, she'd only achieved orgasm that time she won the monthly sweep at the Women's Institute.

The first clue that Kirsty puts the baw in bawdy comes with the title of her titillating tome: The Legacy of Elizabeth Pringle. What kind of name for a sexy heroine is that? Sounds like a cross between a crisp and a sweater. It's like finding that Casanova's first name was Humphrey or Ollie.

I'm not saying Kirsty should have called her book The Legacy of Elizabeth Hooters. It's set on Arran, after all, and most people only bought it to find out which character was Jack McConnell (he's the one with the massive rotavator).

I suppose being Scottish didn't do Kirsty any favours. In Scotland we have a restricted mating season: Sunday, 10.15-10.25pm, just before Sportscene starts. The five minutes before 10.30am are to have a wizz and fetch a beer from the fridge.

This year's shortlist for the bad sex in fiction awards also nearly featured Kirsty's fellow Scot, Andrew Marr, who was pulled up for a squelchy passage in which characters "bucked like deer and squirmed like eels". It might have been set in a zoo. All it needed was a parade of penguins marching in during proceedings.

As London Scots, Andy and Kirsty are two cheeks of the same bottom, so to say. But, while it is one thing to be a Scot on the make, it seems unwise to be a Scot on the making love.