The embarrassment there was largely accidental - though I suppose that Storey quite relished the little frisson of discomfort that stage nudity will always engender in an audience. But I was reminded of the occasion by going to see Mona Hatoum's much-discussed installation at the Tate Gallery's exhibition "Rites of Passage", which ends today. Corps tranger, for those of you who've been away, consists of a circular structure with two small apertures and a dark interior. Inside, projected onto the floor like the image in a camera obscura, is footage of the inside of the artist's body, taken with an endoscope. You stand in worshipful silence ("my body is a temple") as the camera probes and burrows. The result is a moist, pink speleology, a journey strongly reminiscent of the film Alien, with its exploration of organic, threatening corridors. What, you wonder nervously, is lurking round this dark corner?
This is all fine and dandy (and worth seeing, I would say) but by far the most interesting moments come when the image is on the threshold of telling us where we are, moments when the possibility of embarrassment is raised. It might seem that sticking a camera up your butt is the ne plus ultra of artistic candour (not to say a vindication of some gloomy predictions about the ultimate destination of modern art). But actually Ms Hatoum's innards are so unplaceable and unfamiliar a part of the body that there's no discomfort in looking at them. The anxiety arises when we emerge - when we begin to suspect what that thicket of saplings might be and just where that bolster of damp flesh is located. As the camera grazes Ms Hatoum's nipple - a massy outcrop of pink coral - is there a tension in the tiny congregation, a little shiver of embarrassment at this magnified intimacy?
I hope so - if only because a world without embarrassment would be a worse one and because it can sometimes feel as if embarrassment is gradually being excluded as a legitimate response to contemporary art. It is as though embarrassment is a badge of the naive or the unsophisticated, when quite the opposite is the truth. It is the most social of emotions - it's possible to be embarrassed when you're on your own but only if you imagine yourself in company. The sociologist Erving Goffman wrote: "Embarrassment is not an irrational impulse breaking through socially prescribed behaviour but part of this orderly behaviour itself." And we need more of it in a world so blase.
Ms Hatoum isn't alone in addressing the problem - next week, visitors to the Serpentine Gallery will have the chance to see Tilda Swinton, lying for eight hours at a time in a glass vitrine. This art work, called Maybe, has aroused almost as much scornful copy as Corps tranger, but it sounds promisingly squirm-inducing to me. Watching someone sleep is an unusual privilege, fraught with strange feelings of power and hazard. It is undeniably fascinating but, unless the sleeper is a child, you feel a nervous sense of breaking the rules. What if Swinton were to suddenly open her eyes just as you were staring at her face? What will she do about eye contact with the passing crowd? By sleeping in public she risks the familiar embarrassments of unconsciousness - drool and gape. By watching her we take the risk of catching ourselves as peeping Toms, and so exercising our ability to blush.