I don't know whether there's something in my demeanour that encourages relaxed interchange of this nature, or whether telephone engineers in Islington are partial to a cap of tea before setting out on the road, but in case you should misinterpret my sexual orientation and send me careering off into what psychiatrists call 'homosexual panic', I should emphasise that my days don't usually unfold like the opening scenes of a gay porn movie. More's the pity, probably. It would certainly attract comment from the kids (teenagers, and therefore deeply conservative) and my Jungian analyst wife might well have something to say. Hey. What the hell.

The morning soon settled back into reassuring, humdrum British hopelessness when, standing among a spaghetti of phone wires, he announced that it was "crazy in here". Of course it's crazy in here. But is it my fault that I now have three competing phone companies supplying six different lines to this house? No. Blame free market capitalism. It occurred to me that this engineer is obviously in the wrong job - he should try politics. Provided he is sexually ambitious and guilt-free, he could go far. And if he can convince himself he is a Christian and yet still get off on bombing foreigners, then the sky's the limit - he should rise effortlessly to the post of Prime Minister.

Anyway, I have to admit I turned 50 the other day. Julia bought me sushi and we looked at my cards, of which there were a few from good friends basically urging me not to give up. The one from Liesbeth up the road showed a blonde sitting astride a large motorcycle in an open leather jacket, and inside she'd written 'fantasise away'. I'm still wondering how to react to this. I could never quite get into the Russ Meyer buxomatic giganzas thing but okay, let's try a recast of Debra Winger as Tura Satana in Faster Pussycat Kill Kill, miniaturise me so that I'd fit neatly into the breast pocket of any garment she happened to be wearing, and we could drive round on a motor bike and, er, do stuff.

And so to West Hampstead to play tennis with my friend and fellow 50-year-old Charlie Hodges, scriptwriter. Apart from being a naturally gifted player (he started young in South Africa), Charlie is still asking all the big questions, and not just about tennis. He's also the only person I know who can get away with telling jokes. Jokes are problematical, aren't they - veiled repositories of aggression and prejudice. I'll never forget the one Sigmund Freud tells about his train ride from Vienna to Innsbruck, except I can't remember it. I can never remember jokes, always panic halfway through and forget the punchline, but Charlie delivers a well-organised joke, garnished with plausible detail and freshly told as if for the first time. He told me, for example, of an actor by the name of Penis van Lesbian who for no reason he can quite understand found work hard to come by, until his agent hits on the novel idea of changing his name, and he achieves fame, fortune and wealth beyond his dreams as... Dick van Dyke.

I needed to know that. I also needed to know about the man who falls in love with his doctor and repeatedly visits her surgery requiring rectal examination. Eventually the doctor, who apparently does not reciprocate his feelings (I can't think why), refuses to see him. At which point he turns up with a bunch of roses protruding from his anus. The doctor simply won't emerge from her consulting room. "What?" says the man, amazed, "Not even to read the card?"

Over chilled cranberry juice out on Charlie's deck the conversation inevitably turns towards the inescapable realities of late middle age, and by that I mean being checked out for intestinal and prostate cancer. Strange organ, the prostate. Men are told they have one, but they wouldn't know it if they weren't, and it doesn't seem to do much except get cancer. Do I malign it? Probably. The GP who attended to me - a good-looking blonde woman in her thirties - snapped on the white rubber glove, anointed me with lube, then, er, examined me, and said "I'm feeling your prostate now. Mmm. It's nice and smooth." I was, as you can imagine, relieved.

"So you had a woman too," said Charlie after a bit. Not wishing to be anally penetrated by the gnarled and stubby fingers of his grizzled old proctologist, he'd gone down the list of doctors until he came to a woman's name, 'Doctor Paula', and asked whether he could have her, or she could have him, or something. So he got Doctor Paula, or Doctor Paula got him, and it had been okay.

Thereafter the conversation meandered somehow upstream and I found myself talking rubbish about the curious inability of the English upper middle classes to achieve world domination on the sportsfield. I said I thought it had to do with the fact that they were all thrashed at prep school - a kind of defilement, a kind of violation encouraging a masochistic response to the world. Could it be that English sportsmen prefer the pain of loss to the excitement of victory... could it be that in a strictly metaphorical sense, you understand, they prefer to take it up the ass?

Charlie didn't look convinced. But it was all very well for him. He had, after all, beaten me 6-2, 6-2.