Sex chat without registes
They are allowed to sign up for free as a way of ensuring the numbers are balanced between the sexes.
I register, and enter the murky world of two-timing technology, taking note of the warning on the site: "Not all affairs have a positive effect on a marriage." What a masterpiece of understatement.
But it claims to have more than 100,000 members in the UK.
Many of them are middle-class, many have young children.
Reading it on my laptop in the aptly named Cafe Affaire in central London, I consider what she really wants: a no-strings-attached sexual relationship.
What I don't know is how her husband will feel about it. Aside from the little matter of her marital status, she also believes I have a wife, but she doesn't care.
One woman sends me a message heavily laden with sexual innuendo and I come to regard her as the mistress of the single entendre. Another woman's first contact with me included a plan for a day out together, including visits to art galleries, a stroll round a park and then "a few hours under the duvet". I'm later propositioned by someone who tells me she has an hourglass figure.
Her photograph reveals that the hour has stretched to 90 minutes.
Your picture can be viewed only if you give a password to the person with whom you are conversing.
She has declined to tell me her name, so I have to think of her as her web sobriquet.
This is how I find myself waiting for "Sophia Loren".
I'm already starting to feel like I've had enough of this experiment.
But if I'm going to find out what really makes these women tick, I need to leave the safety of the virtual world and see them for myself. I arrange to meet a 41-year-old mother of two who misses "romance and flirting", in a cafe in two days' time.