What could be more salubrious than taking your mother-in-law to a matinée? As it turned out, the play, Six Characters in Search of an Author, featured a fair dose of incest and rape, but she’s an open-minded gal. Besides, this turned out to be immaterial. I had come unstuck before I even entered the theatre.

Our meeting was set for 2.30pm on Shaftesbury Avenue. I arrived at Piccadilly Circus at 2.15pm, but in my haste to be early, I had not thought about lunch - and did not fancy Pirandello on an empty stomach.

Not long ago, I would have nipped to the New Piccadilly café on Denman Street for a bacon butty. But it’s gone. And, moping hungrily towards the theatre, I could think of nowhere in this tourist hellhole that would tally with the amount of cash I had in my pocket. And then I looked up and saw McDonald’s.

Now I haven’t been to McDonald’s for years, thanks to the revelations of Fast Food Nation and, it’s true, the rise of the West Cornwall Pasty Company. But times are hard. And right now £1.19 for a double cheeseburger sounded like a deal.

I decided to scoff the thing as quickly as poss, standing upright, on the premises, then eat a lot of gum and scoot to the theatre. Nobody, except other people who eat in McDonald’s, would see me here, so my reputation would be safe. I drew breath and lost myself in the business of eating. Until:

"Richard?" As if in a bad dream, my mother-in-law was standing in front of me. "We thought it was you!"

[ITAL]We?[/ITAL]I wiped about of ketchup off my chin and looked to where she was pointing. She had been out with her friend and her friend’s daughter - and the daughter had, improbably, recognised me from across the road, through the window, from a photo! They waved, sceptically.

There was nothing I could do to regain my cool. I had to hold my breath as I kissed hellos, subtly pick bits of orange cheese from teeth, surreptitously slip the half eaten item into my pocket. I felt as if I’d been caught in a brothel.

There is much fashionable talk about the credit crunch - even a strain of competitive thrift emerging among the middle classes. But for every virtuous saving we might make, such as cycling to work, there are dubious ones we could also make, though our instinct is to turn our nose up. But if you are serious about thrift, shouldn’t snobbery go, along with champagne?

My mother-in-law and her friends had great fun with my embarassment. But the burger? Delicious, and filling, too.