Saturday, 9th June, 4.30pm or so. A painfully hot day in London. Well, painful if you insist on wearing a black suit with a lining purely because that’s who you are. Should have worn the white linen one, only it doesn’t last long before needing a good dry cleaning, while the black ones are more practical. For a person living hand-to-mouth, I must spend far more on dry cleaning than I do on food. But what are luxuries to some are essentials to me.

I am standing on Waterloo Bridge, the South Bank end by the National Theatre. With me is my mother. We have just seen the matinee performance of ‘A Matter Of Life And Death’ by the Knee High Company, and are about to walk across the bridge and into the main part of the city.

Then my mother says, “Oh, look.” And I stop nattering on about whatever I am nattering on about and see if I can see what she sees. Always had a problem with that one. I rarely notice what others notice when walking in company, most of my badly-wired brain dedicated to the act of being in company itself. It’s only when I’m alone do I really notice my surroundings.

So I look up and I do notice something unusual. Lots of bronze statues of nude men on the roof of the Hayward Gallery and surrounding buildings. I know exactly what they are, as will any Londoner with the slightest interest in the arts. They are the work of artist Antony Gormley, and are based on body casts of his own unadorned physique. We passed one earlier on, on the bridge itself. He’s been doing variations on this theme for so long now, I feel more familiar with Mr Gormley’s genitals than I am with my own.

Funny how we like modern artists to more or less stick with the one sort of idea. When Damien Hirst dies, regardless of his coloured dot paintings and medicine cabinets and anything else he does, the obituaries will have the animals in formaldehyde. For David Hockney it won’t be his photo montages or fax machine pictures or the opera set designs or the paintings of his dog. It’s going to be the swimming pools. Oh, and maybe that one of the couple and the cat. Henry Moore – big lumpy human-like sculptures in parks. Barbara Hepworth – big lumpy abstract sculptures in parks. And even though Mr Gormley is currently exhibiting a new kind of installation – a huge cube of fake fog visitors can walk into – he’s still The One Who Does The Body Casts. Still, it’s not if he’s resisting the label. This time, his body-cast bronzes are on the rooftops of London.

“Oh yes,” I say to Mum. “I see them. Lots of nude men on the roofs.”

“Never mind those. I meant the real nudes on bikes. In front of us.”

My eyes had skimmed over what I thought was some ordinary group of cyclists mounting the bridge. But now I see what she means. The cyclists are the first in a long parade of hundreds, blocking our way forward. And they are naked.

Nude Gormleys above, real nudes on bikes below. My mother standing next to me. The phrase “I don’t know where to look” springs to mind.

Some carry banners protesting against oil-guzzling vehicles stealing the roads, but whatever the message of protest is, it is rather upstaged by the mass nudity on display. Mostly men, about 35% women, pale and pink flesh everywhere. Some are slightly less naked – a few underpants and shorts or bikinis. One or two are even fully clothed. But the vast majority have it all out. Just as well it’s a hot day.

As is usually the case, many bodies on display are less Michaelangelo and more Michael Moore (in every sense). But I’m happy for their cause.

My unease, though, is the one experienced when watching a movie with one’s parents, and there’s a sex scene. Except this is real. I feel I am essentially staring at a parade of real genitals with my mother. And me just out of therapy.

She thinks it’s all rather fun, of course. It’s me that’s mortified. Mortified, and overdressed, in a sea of the undressed.

One or two of the younger riders are actually rather comely. And my thoughts are that, with my luck and my image, there’s no reason not to suspect that this could be my last exposure to attractive naked flesh, between now and the grave. Standing on the street, fully dressed, with my Mum at my side.

And so, as this atypical event is happening, I am thinking, “typical”.