'I'd like to hear your take on my mad neighbour,' announces Dan from his hands-free in the car.
'Mm?' I slacken my pace. Dan doesn't like wind interference or heavy breathing.
'She's taken to giving farm tours, towing visitors round behind the tractor. She's put a sofa in the wagon and they sit there, drinking wine and admiring her Portland rams.'
'Sounds rather fun.' I flop down on a park bench overlooking the Serpentine. Pigeons are flapping around a toddler, intercepting the chunks of bread he's throwing to the unlucky ducks.
'So then this Bentley appeared in her drive, and it was still there the next morning. The next day there was an Aston Martin - still there the next morning - then the next day, a Ferrari. There's been a constant stream of them. All there the following morning. So then she comes up to me today and says, "I'm going away on holiday, if you see a man in a white Range Rover hanging around, he's one of my Gentleman Callers and you can tell him he's not welcome here any more, because he's not."' Dan lets out an exuberant belly laugh. 'So what do you think, Lize? What can it all mean? Is she a prostitute?' He says it with an endearing touch of naivety, suggesting one who expects to be laughingly given a logical alternative explanation.
'Of course she is!' I snap my fingers and glare at Dolly, who is sniffing around the toddler's buggy, hoovering up stray breadcrumbs.
'Really? "Gentleman Callers!" What else can it mean?'
'Nothing. She's definitely a prozzie. Although she probably doesn't refer to herself as such. She probably calls herself a high-class ... farm hand.'
'Farm hand!' guffaws Dan.
'But what I'd like to know is how come they've all got such posh cars. I've never met anyone like that around Candlebury.'
'I presume she's signed up to ivegotanincrediblyexpensivecar.com. I did go on match.com to see if I could find her, but it's full of fairly average people, isn't it?'
'Yees,' I agree absent-mindedly. My mind has sped into fifth gear. Ivegotanincrediblyexpensivecar.com! Maybe this is the answer to my dire straits.
'I did somehow end up on Rate My Prostitute once,' Dan continues conversationally, 'and I was interested to note that what makes a good prostitute is off-street parking and a nice cup of tea.'
'Well that's the answer to why she's so popular! She probably pulls them in with a picture of her drive. "Come and indulge in a lavish forecourt..."'
'"...and a nice cup of Earl Grey!"'
Bang go my chances of being a high-class call-girl, though. No forecourt. It's impossible to park round here after 6.30pm.
Hmmm. Will just check out ivegotanincrediblyexpensivecar.com. Oops. Google Chrome couldn't find it. Well, that was too much to hope for. Google 'dating site for rich people with posh cars.' Here we are! www.millionairematch.com. With a big red button saying, FIND A MILLIONAIRE NOW! Click.