"I am rarely the first port of call for would-be adulterers," says David Miller. "By the time people come to me, there are already cracks in their core relationship." Miller, a social psychology graduate, owns a dating agency with a difference - Loving Links caters exclusively for married people seeking outside relationships. He has been operating since 1996 but was not the first in the field; Charlotte Graham, a retired secretary, set up a similar operation, Additions, two years earlier and claims Miller pinched her idea.
The premise behind both agencies is simple. Advertisements in broadsheets and women's glossies invite readers to subscribe to newsletters in which men and women advertise for discreet "friendships." It's a small market - Miller claims 700 clients, Graham 400 - with fees set high enough to attract what Miller describes as "high-quality people".
It's easy to see the attraction for men. But what sort of women use these agencies, and why? Having spoken to a dozen or so clients, I found a surprisingly homogeneous group - middle-class, middle-aged, middle England, often with a middle-income job. Listening to them, I was struck by their candour and self-awareness. They talked eloquently of loneliness in marriage, of disappointments and deflated expectations. They also described the release, freedom and fulfilment they'd found through the agencies.
None had taken the first step without qualms: "I agonised for weeks before I plucked up the courage..." Surprisingly, once enrolled, they felt the agencies conferred a sense, almost, of community. One woman talked of "the Additions family," another described Loving Links as "a self-selecting group of nice people", a third relished "the feeling of being in a secret club".
Secrecy is paramount to clients and both agencies claim high levels of "discretion". Many of the women believed discovery would spell disaster. "He'd want out but that's the risk I take..." "That would be that for my marriage..." Only two were more optimistic: "We'd survive it now. I think..." "It would hurt him, but we're mature enough to put the children first."
What if the boot were on the other foot? "I'd say good luck to him..." "Fine, as long as he didn't wave it under my nose..." "If an affair made him a better person to live with, I'd probably feel OK." But none sounded really convinced: "You just don't know until it happens."
Most of the interviewees felt burdened by the deceit of leading a double life. But often, it seemed to me, the cuckolded husbands brought infidelity upon themselves. These women weren't listened to at home, felt undervalued intellectually, and resented being reduced to cyphers - wife, mother, homemaker.
So why had they not discussed these dissatisfactions with their partners? "After years of marriage, you fall into habits of non-communication..." "It's our unspoken no-go area..." "I think he'd get defensive and angry."
Moral arbiters may condemn Miller and Graham as panderers and brand their clients selfish deceivers. But I found no Jezebels, just decent, dignified women doing their best to get by in difficult situations.
Case Study One: Heather typifies the Loving Links client. She is 42, London-based and balances part-time consultancy with family life. She loves her husband but four years ago, "aching because he wanted the marriage to be virtually platonic", she "stumbled" into an affair. Although it ended badly, she craved the romance and sexual fulfilment she'd found. So when she read about the agency, "it struck a real chord".
"I felt great trepidation but I needed to replace what I was missing at home. On a date, I am truly myself rather than someone's mum, someone's wife, someone's colleague. I can be just Heather again. Paradoxically, seeing other men has strengthened my marriage - it's made me more giving at home, less ratty and frustrated, able to be a better partner and parent.
Heather has dated two dozen men, of whom a handful have become close confidantes and only two lovers. "I want to have fun with, talk freely to, people who can explore ideas - good friends, in short.
"Married women can't have personal male friends they can talk to confidentially; however platonic, people always assume it's sexual. I need men - and I go back to this because it's important - who see me as myself, who let me throw off those yokes of family, of home."
Heather's biggest fear is escalation. "One day I might feel something a great deal stronger for someone else. But with Loving Links, unlike my spontaneous affair, the boundaries are drawn at the very outset. Everyone's human and people fall in love. But my family always comes first and that grounds me."
Case Study Two: Stephanie, a quiet, thoughtful professional in her mid-40s, knows her infidelity would hurt her husband. So why sign up with Additions? "There's a lot which is very good in my marriage but my husband has been impotent for years. I tried to live with it but I became very restless and unhappy. When impotence is discussed, it's usually from a male perspective. No one listens to the women's voices; no one asks 'what about the wife, what is she going through'.
"I saw the advertisement and thought 'here is something that maybe can make me a happier person and help me keep my marriage together." She has now had two affairs, but have they brought the hoped-for benefit? "If I hadn't had these flings, I think the marriage wouldn't have survived and that would have hurt my husband much more. Once I realised I needed to do this for myself, conventional morality went out the window. For me, what I'm doing is not immoral: I didn't want these flings as an extra, I was pushed into this situation. That may sound like self-justification but I'm not blaming my husband at all.
"Flings aside, I've met some really nice people through Additions, generally guys who are simply lonely with no intellectual or emotional engagement in their marriage. With me it's the opposite; I have real companionship at home with a lovely person yet I crave the physical side. But that has to be with someone who's become a friend, someone on my wavelength, so both my flings have been fairly long-term."
There's a world of difference between antiseptic married sex and the wildly erotic sex you have with someone new, especially when it can't possibly lead to anything. You get all the best bits - the fun, the laughter, the wining and dining - without having to get tangled up in each other's lives."
Using the agency has also broadened her range of social contact. "I'm left-wing and arty and so are my friends. But through Links I've met Telegraph types, army officers and so on. I find their views bizarre," she chuckles, adding: "Most of the men have been really great and I've never met any saddos or losers."
Stephanie has found the most common complaint among the men she meets is the withdrawal of marital sex. "If wives can't be bothered with sex at all, they shouldn't be surprised if their man turns elsewhere." Even if that risks a broken marriage? "No, but using an agency is a safeguard against that. The rules of engagement are crystal clear from the beginning - the men want to preserve their marriages and I don't want to be half a couple again. So they're perfectly safe in my hands."