In the end, we agree to part and she wishes me luck and assures me I'll find the perfect paramour. This was like having a meeting with a new accountant with a helping of self-disgust thrown in.

Later on I'm perplexed when she sends me two flirty text messages.

Her photograph reveals that the hour has stretched to 90 minutes.

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.

She wants instant gratification even though we've exchanged only a few words online.

Your picture can be viewed only if you give a password to the person with whom you are conversing.

The idea is presumably to safeguard people from searching for their own spouses on the site - though how a husband would explain to his errant wife how he came to stumble across her picture on a website for adulterers, I don't know.

But in the modern world, in which the internet has become a vehicle for all manner of impropriety, she regards this kind of behaviour as perfectly acceptable.

We have encountered one another via an internet dating service established for the sole purpose of enabling married people to commit adultery.

But she is an old hand at this type of encounter and tells me she's met many men through the site, and that I was probably the only one who hadn't lied about my age.

"Sophia" tells me she thinks relationships have a shelf life of about ten years before boredom sets in, but that she stays married to ensure her children have a stable home.

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.