"My preference is for a man who is much younger than me with rugged features," says one. This is a way of paying someone a compliment without typing out the words. And over the course of a week I get almost 100 replies, messages and propositions.Postings such as: "I want a man who can look after me and knows how to treat a woman. I'm surprised and unsettled by the forward tone of some of the material. Determined to avoid the connotations, I reply: "The Beatles." I never hear from her again.

And all of them are looking for an opportunity to betray their spouses. But I wanted to find out what sort of woman uses such a site.

So I paid £119 for a month's membership, giving me an entre to thousands of faithless females.

National Sex Offender Registry is celebrating 17 years of free service with no advertising.

"I want a man with a personality and looks to take my breath away." These are the requirements of the dark-haired, dark-eyed, 37-year-old Asian beauty who has sent me her romantic wish list.

"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.

After discussing how mundane marriages become and avoiding questions about my personal life, it's clear we're past our sell-by date after ten minutes, never mind ten years. She doesn't want to discuss her husband, and I feel uneasy talking to her.Despite this, she still seems keen to flirt with me.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.She wants instant gratification even though we've exchanged only a few words online.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.She has declined to tell me her name, so I have to think of her as her web sobriquet.