Once upon a time we all knew the kind of man who kept a mistress: the Prince of Wales, landed gentry, Tory politicians, footballers, film stars, poets, artists, plus other assorted cads and bounders. They may have been grade A shits, but you could say this one thing for them, they didn't pretend to be family men (well, not until David Mellor ruined things by posing with his family at the homestead's gate).
Nowadays, it seems, you just can't tell. The nation has been shocked to its core by the allegations that rumple-faced family man and chef Gordon Ramsay has a mistress. If the story is true, I bet he's regretting some of those book titles: Gordon Ramsay's Secrets, Gordon Ramsay's Passion for Flavour, and the puritan's favourite, Gordon Ramsay's Just Desserts.
We haven't been so wounded since it was revealed that natural blond, family man, and housewives' choice, Boris Johnson, had a bit on the side. (Whoever next? Rolf Harris? The Archbishop of Canterbury?) Mind you, family man Chief Constable Mike Todd had 38 dalliances in six years, which even makes the late, legendary swordsman Alan Clarke MP look half-hearted.
But why are we so startled by these claims? Shouldn't we acknowledge that the mistress is always with us, like the weather. Whenever a man has an excess of fame, wealth or power, there will be women keen to divest him of a little of that magic in exchange for her lithesome form.
I'm not saying such men are the innocent dupes of wicked, female wiles – but the combination of turbo-charged careers with absences from home and an innate male susceptibility to flattery can make for sexual Armageddon. Nor is it coincidence that many such affairs coincide with the dog days of nursery tedium and grumpy, sore-nippled wives.
What has changed over the years, however, is the nature of the mistress's role. There was a time when a mistress knew her place. She dispensed exotic sex and guaranteed discretion in return for diamond necklaces and a bijou flat in Maida Vale.
I was once at a lunch party in Provence when the host pointed out a fellow guest, a striking author in her fifties, and said that she was a duke's mistress with a house on his estate and, "that's how she affords to write all those books".
One of the best pieces I ever ran when I edited The Erotic Review was a connoisseur's guide to the other woman by the fabulously sexy classicist and author, Lizzie Speller.
Nowadays we loosely attribute the term mistress to any woman who gives a half-hearted blow-job to a C-list celeb, but Speller rightly protested out that the true definition "would be a woman in a relationship with a married man who is supporting her in a parallel ménage to the one in which he maintains his wife and children".
Speller emphasised the importance of the financial transaction: she wrote that the true mistress earns her upkeep by trading "her occult sexual promise. She offers not just a body, but wit and a good brain, the better, it is believed, to develop recondite sexual practices, which might become onerous, even injurious to health, if explored on a more than part-time basis".
Ramsay's alleged mistress, Sarah Symonds, may well have fulfilled the latter part of Speller's bargain when she reportedly liaised with the chef in a swanky London hotel, armed only with amyl nitrate and two bottles of white wine. But judging by the tone of her book, Having an Affair? A Handbook For The Other Woman (top advice: "Act like a man. Don't get hurt and use him as much as he's using you"), the financial transaction she aspired to was a rather more vulgar affair.
The sort of mistress Speller was referring to wouldn't have been seen dead buying her own plonk, let alone dashing down from Wales to do the dirty in a mere 75 minutes, as Symonds did.
So should we be more French about the whole business? Accept that a married man in possession of a good fortune – or high office – must be in want of a mistress? At least the French tradition of cinq a sept offers reciprocal rights to the bored housewife. But I'm not sure we could follow this model.
The British have never really enjoyed seeing their pleasures open and formalised. What goes on beneath the table, the unacknowledged footsie, is so much more appealing to our covert nature. I just wish we would lay off the constant moralising about naughty Gordy and poor humiliated Tana. I am sure they can address to the matter in private and come to their own mutually satisfactory resolutions: that's what being British is all about.