I have discovered, since moving to France ten years ago, that the French have a different attitude from ours when it comes to marriage and fidelity. And it is not only the men. In a survey carried out by the Institut Français d’Opinion Publique, only 2 per cent of French women said they would never consider having an affair.

Another incident that has stuck in my mind happened not long after we had moved to rural France. I was due to meet a French friend for lunch. She was 15 minutes late. “So sorry,” Claire told me breathlessly when she arrived, grinning from ear to ear. “I had to see my lover and you know, well, one thing led to another.”

“Your lover? Does your husband know you have a lover?”

She laughed. “I’m sure he does, although we never discuss it. Here in France everyone does their own thing.”

“I don’t,” I told her. “My husband would kill me.” She gave me a Gallic shrug. “Then don’t tell him.”

Several years down the line I’m less shocked by this kind of thing. Have I been converted by living in France? Would I have an affair? Even forgive an affair?

Yes, I would. What living in France has taught me is that sex can be just another sensual pleasure. I would be far more hurt if my husband told me that he would rather go for our favourite walk across the vineyards with another woman than if he said he wanted to have sex with her.

I have concluded that, in a funny way, sex can almost be less intimate than spending time with someone and getting to know and love them. A lot of marriages in the UK end because one of the partners has a fling that means nothing. I think that’s a real shame. How can you seriously expect someone not to be tempted by a little adventure?

When researching a book a few years ago about French women I travelled to Paris every few weeks. On one of my trips I met a dashing French politician. He made it clear that he was up for a liaison. I was seriously tempted, but in the end I decided against it, partly because my (English) husband has yet fully to accept the French philosophy of marriage, but also, when it came down to it, what I liked about my would-be French lover was the sense of anticipation, and the fact that he inspired me to take care of myself. I didn’t need to take things farther. But I admit that that’s not very French of me.

So how do the French make it work? A girlfriend who lives in Toulouse told me about her husband, who goes up to Paris every month “to have his hair cut”.

“But when he comes back, his hair is exactly the same,” she laughed. “I can’t believe how stupid he is.” But doesn’t she mind? “Not at all,” she said. “It gives me the liberté to do my own thing.”

The French notion of liberté is at the very heart of their attitude towards fidelity and marriage. As Professor Michael Worton, vice-provost and Fielden Professor of French Language and Literature at UCL, tells me: “The notion of freedom is deeply inscribed in the French psyche. Marrying and then misbehaving is seen as being free.” Are they right? After all, their divorce rate is slightly lower than ours is — in Britain it is currently 45 per cent.

“The family is the main issue,” says Delphine, a French friend and mother of three. “The reason we accept the natural human urge to wander is that the family is more important than the individual, and when I talk about the family I mean the extended family; we are talking about 50 or 60 people. So if you break up the couple, you affect all those people, it’s just not worth it.”

Delphine had not been unfaithful until she discovered that her husband had slept with a colleague on a business trip.

“At first I was a little upset, but then I thought about it and the effect it had had on our marriage, life or family. None was the answer. So I just went out and had my own petite aventure, which made me feel not only avenged but rather sexier and younger than I felt before.”

I started to wonder if the French have a point. But what happens if you fall in love with your fling? As the character of Audrey in my novel Love in a Warm Climate says on the subject: “I fall in love with them all in a small way.” But not in a way that would ever threaten the family.

What shocks the French more than a bit of “side salad” as one French male friend of mine puts it, is how uptight we British are about affairs. “We all know that a man who does not have sex is a monster,” he says. “Which is why none of us mind our politicians having mistresses.”

As you would expect from this egalitarian society, women are not condemned for philandering either. “We all talk about our affairs entre nous,” my friend Delphine says. “And of course we are loyal to our girlfriends and remain silent.”

The silence is part of the French code of extra-marital conduct, which includes a heavy dose of discretion. I get the impression that you would be more vilified for behaving in an indiscreet manner than a faithless one. And this again goes back to the enormous respect they have for the institution of marriage and the family.

Interestingly the French have parameters for their liaisons, such as their famous cinq à sept, “the easiest hours to hide” as Charles puts it. It’s fine to have an affair, but you don’t rub it in your partner’s face. One of my friends actually thought in all seriousness that our “tea” was the same thing. That rather than eating scones and drinking Earl Grey we were all busy indulging in salacious extra-marital encounters every afternoon at 4pm. If only.

Thus affairs are almost institutionalised in France. Marriage may be sacred, but sex is allowed. So if you’re having sex with someone else, does that mean that marriage is just a vehicle for bringing up kids?

“Quite the opposite,” says my French friend Julie. “Being sexually active outside the marriage keeps the marriage interesting. French women sacrifice everything to be attractive, even straight after child-birth, because if they don’t, there are plenty of women out there who will.”

Two of my children were born in France and both times I was struck by two major differences to my childbirth experience in the UK. First, I was practically the only woman on the ward who breastfed. The French women were far more interested in regaining their liberté to saddle themselves with a hungry newborn. Second, once I was home from hospital the state helpfully arranged for me to go through the excruciatingly embarrassing experience of pereneal re-training, which involved a (male) doctor donning plastic gloves to examine how fit or otherwise I was “down there”. At the time I asked Claire what it was all in aid of. “It’s to get you back into shape for your husband,” she told me. “And whoever else.” Very French.

Helena Frith Powell is the author of Love in a Warm Climatepublished by Gibson Square at £7.99