I'm having a roaring time in a Rue de Rivoli café with Sophie Fontanel, a smart Elle senior fashion editor who is demonstrating how to seduce any man – our waiter, say – for the benefit of our women readers.
The key, she says, is "ambiguity". This is understood in France to be somewhat looser than what we'd call "mystery". "Any Frenchwoman can do it," she asserts. "Say you wear a nice little black jumper." (No visible cleavage, of course; that would be pathetically obvious.) "Add a pencil skirt, nice pumps, not even very high-heeled. When the man comes to take your order, look him in the eye with a smile. You could say something like 'Ah, if you're looking at me like that. . .' and leave it hanging."
None of this, you understand, is blatant; everyone remains with their options intact. Salade Niçoise? Badoit water? A carefree little cinq-à-sept? Or just nothing, simply that both protagonists' spirits have been lifted for a moment by a little light flirting. "This is part of French civilisation," Fontanel jokes. As for Americans, she gives the impression of feeling they're on a different planet. "They're so puritan. They have no conception of how to be playful."
Fontanel isn't what you'd expect of the author of a bestseller on how she gave up sex. Yet L'Envie, her 12th book (soon to be published in English as The Art of Sleeping Alone) sold an amazing 150,000 copies in a few weeks. "It hit a chord," she says. "I remember being on holiday in the South of France when it came out, in August 2011, and getting a telephone call from my publishers who said, 'Hop on a train, come back this instant: the evening RMC radio news show want you on as their main guest.' And then it never stopped."
People called in, stopped her in the street, wrote and emailed her. Most sounded elated that "finally, someone was saying this shocking thing in our oversexualised society: that sex is not, in fact, compulsory.
'For a long while, I chose to live in what was perhaps the worst insubordination of our times: I had no sex life," her elegantly written book starts. Neither novel nor essay, it uses episodes of her life to make the case that women should not give up high expectations – that no sex is infinitely preferable to bad sex.
"I spent the first 10 years of my adult life having, frankly, disappointing sex," she says. "It was mechanical, even when it gave me pleasure."
She had friends; she had an exciting job as a journalist; she travelled to London and Milan Fashion Week. There were brief affairs with men; more often than not personable, who saw a tall, soignée brunette with an engaging smile. There were longer-lasting liaisons with men who expected her to conform to their desires.
"One would wake me up at 4.30am or 5am to make love, night after night, and didn't care that I couldn't go back to sleep afterwards. Yet if I had to get up at night to get a glass of water and disturbed him, there were no end of recriminations."
You'd say they used her, but it's not in Fontanel's style to pose as a victim.
One day she went off alone for a skiing holiday, and experienced a complete liberation. "Sleeping alone in a big bed! Skiing on my own, at my own speed! You can't imagine how happy I was." She had an epiphany then and there, and decided to take a sabbatical from the times of mandatory sex. It lasted 12 years.
She writes that she had had enough of being "taken and shaken", but she has also said that "from someone you are madly in love with, the same roughness can be intensely exciting". It is, first and foremost, a question of choice.
You can have the most outlandish sexual experiences, she says today, write them up like contemporary art dealer Catherine Millet – the author of the 2001 best-selling shocker The Sexual Life of Catherine M, which tells of Millet's endless search for sex with unknowns – and no one will want to appear so gauche as to even suggest moral criticism. Admitting to abstinence? Drop the word at a dinner party, and see everyone's scandalised faces. To them, it's the worst obscenity. No wonder that early on Fontanel invented imaginary lovers rather than face her friends' reactions.
'I've been called frigid, abnormal, bitter, neurotic, a lesbian." Acquaintances accused her of regressing to the most reactionary brand of Catholicism. L'Envie woke the inner Neanderthal in seemingly sophisticated men in her circles. One friend raged at her: "How could you do this? What if my wife reads your book?"
Other men thanked her, like so many women. "They feel the pressure as well," she says. "They let themselves be defined by performance. And yet, some of the most interesting characters exist above sex. It's not an infirmity. They simply have better things to do with their lives."
At the end of her book, the first-person character who is and isn't Sophie Fontanel meets a man. She had not committed to a dry sex life; just one respecting of her desire. "Whatever you do," she says now, "you have to be brave. True to yourself."