Epine D'Amour, Les Abattoirs, Marseilles, **

Tattooed along the inside of the performance artist John Kamikaze's arms are the words "pain" and "freak" – and for many people, those two phrases will just about sum up the experience of watching Epine d'Amour (Thorn of Love). Coming to Selfridges in London later this month as part of the shop's "Body Craze" season, it is not the sort of show to take your granny to. Nor will the piece – which features acts of sado-masochism – please our more judgemental newspapers.

The show is on the borderline between S&M and art, and audiences have to ask themselves searching questions about whether they are kinky voyeurs or witnesses at a ground-breaking artistic happening. Like me, you may find yourself watching much of the show in Dr Who mode – through splayed fingers from behind an imaginary sofa.

At a recent performance in a disused Marseilles abattoir – possibly the weirdest venue I have been in – I noticed many audience members turning away at the moment when Kamikaze stuck a huge needle through his Adam's apple.

Be warned: that is not the most horrendous thing that Kamikaze, a former circus performer from Scotland with more tattoos than Cape Fear's Max Cady, and his cohorts, Helmut Kirchmeier and Wes Westenburger, inflict on themselves. In an unhinged homage to Busby Berkeley, Kamikaze and Kirchmeier "swim" through pools of broken glass.

Meanwhile, like a twisted cartoon character, Westenburger gleefully pulls a volunteer round on an office chair attached by a chain to his penis. That particular moment brings a new meaning to the phrase "suffering for your art". Later, in a truly memorable finale accompanied by atmospheric music, Kamikaze flies across the stage suspended on two meat hooks pierced through his skin. Talk about a big finish.

Watching this trio bleed on our behalf in this show directed by the noted French circus maestro, Pierrot Bidon, you think, "there must be an easier way to earn a living". For all that, there is a slapstick tone to the piece that owes much to the comic tradition of Chaplin or Keaton. It also makes you reassess your attitude to such themes as pleasure and pain.

At a time when so much London theatre has a soporific effect on its audience, Epine d'Amour at least has the virtue of making you sit up and take notice. Like XXX, the "simulated sex" show at the Riverside that got the tabloids in such a lather last week, this is a prime example of "shock art". You may not enjoy it in the conventional sense, but you'll never forget it.

At Selfridges, Oxford St, London WC1 (08708 377 377) on 27 May