Affairs fascinate us all -- but has France's first lady gone too far this time?
The Gallic attitude to fidelity can shock us, says Helena Frith Powell
They say a week is a long time in politics, and in French politics it needs to be. France's First Lady, Valérie Trierweiler, certainly had a lot to pack in during her working week, sleeping, as is alleged in a new book, with both François Hollande, the socialist president, and Patrick Devedjian, a Right-wing politician. Oh, and she was also married to her fellow Paris Match journalist Denis Trierweiler at the time.
Nothing unusual in that, you might think -- the French are always up to some skulduggery, and the women are the worst.
Just look at the author Sidonie-Gabrielle Colette, who had an affair with her stepson, among others.
Or the heroines of French literature, such as the faithless Madame Bovary and Thérèse Raquin, who murdered her husband with the help of her lover.
I have spent years writing about French women, the French art of love and how the French seem able to get away with having affairs.
I have been an advocate of the French way of life, arguing that we should all get over our puritanical hang-ups and treat sex a bit more like the French do, as something to enjoy and not take too seriously.
Rather like a piece of cheese: as long as you don't overdo it, no one gets hurt (or fat). The heroine of my latest novel gets in touch with her inner Frenchwoman when her husband is unfaithful to her, and the effect on her is fabulous.
But this latest shenanigan has surprised even me. For a start, if the allegations are true, each man knew that the other was sleeping with Miss Trierweiler.
Call me old-fashioned, but what man would put up with that? I don't buy the line that they had "the greatest of respect for one another".
I can only assume they were both hoping she would share the other lover's political secrets during some indiscreet pillow talk.
I am also quite surprised by Miss Trierweiler. Granted, most of the French women I have interviewed have admitted to enjoying a little of what they call "side salad" at some stage during their relationships.
They see it as a healthy way to stay sexy, young and vibrant.
As one serial philanderer told me: "No anti-ageing cream can give you the youthful glow an afternoon of illicit sex can."
But to have two lovers, as well as a husband waiting for you at home, isn't that just a bit greedy? I mean, it's all very well if you're spending an adolescent summer doing little but cycling, wearing stripy shirts and enjoying a ménage à trois in the style of Jules et Jim, but we're talking about middle-aged (heaven forbid) professionals here.
In an effort to understand what Miss Trierweiler was up to, I spoke to some French girlfriends.
The consensus seems to be that she was keener on the Right-winger, but because he wouldn't commit to her, she started a dalliance with Hollande.
"Maybe she thought it would galvanise Devedjian into action," says one Paris-based friend. "It was a good plan, but it backfired."
"Hell hath no fury like a Frenchwoman whose lover refuses to leave his wife for her," says another.
One interesting aspect is the effect this scandal has had on all their careers.
It seems there will be few or no consequences. Everyone hates Miss Trierweiler already. Her nicknames include "First B----" and "The Rottweiler". She is officially France's least popular First Lady ever; so no change there. The two men remain so far unscathed. And Devedjian has now said he will sue for defamation and invasion of privacy.
Can you imagine, though, if this story involved Michelle and Barack Obama? The political consequences would be enormous. The whole country would come to a standstill. But most French people just give a Gallic shrug and say "Et alors?"
Earlier this year we had the hyper-philanderer Dominique Strauss-Kahn's saga, and more sordid details about his orgies are surfacing. (Were Miss Trierweiler and her entourage ever invited, I wonder? They could have doubled the numbers at a stroke.)
But when he was arrested, the most ignominious aspect to most French people was the idea that he might have to wear an orange jumpsuit.
I think that perhaps we don't get quite so hysterical about French dalliances because we expect them.
The French, after all, are the arbiters of the affair. They invented the cinq à sept; in this part of the world we have happy hour between five and seven, or tea.
Frenchwomen don suspenders and go off seducing people -- that's what they do. There's no point in getting all uppity about it; they're not about to change.
And what a shame it would be if they did.
Because while a week in politics really does feel like a long time over here, in France it must just whizz by.
Helena Frith Powell is the author of Love in a Warm Climate (Gibson Square)