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.
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.
After a quick search, I get the measure of the women on the site.
"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.
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.
It may sound like an unpleasant niche website for a handful of amoral people to whom wedding vows never meant very much.
But it claims to have more than 100,000 members in the UK.
Reading between the lines, I suspect she wants to meet again.