Christopher Green in Prurience
Christopher Green in Prurience
© James Norton

Sex is real; Porn is pretend. That's one of the mantras at the heart of the Prurience method – a global support group for those addicted to online pornography. It cuts right to the quick of performance artist Christopher Green's sly self-help satire: an immersive theatre piece that gradually starts to resemble one big circle jerk.

Green plays the group leader, Chris, with a voice like quilted loo paper and a ginger ponytail that swings between his shoulder blades. He wears bad jeans and a saintly smile, and comes across as insipid and air-headed. "Grab a seat, guys," he trills, beckoning to the stacks of blue chairs lining one wall. "Make a circle."

It's a neat spoof of support groups – those cults of lukewarm psychobabble and strength in numbers with their weak tea and their weaker smiles. There are DIY name badges, a bowl full of hand-written "expectations" collected from the audience and a whiteboard with a welcome message. We run through a series of exercises: shaking hands with strangers and breathing as one. We close our eyes and confess. There's even a group song. It's only five minutes in that we clock why we're here: the small matter of our porn habits. "Now, who'd like to share their first experience of pornography? Anyone?"

Chris is, you sense, a groupie himself. Something about his lack of command, the way he "invites" us to do this or that and struggles to silence the group, suggests a pain beneath the surface. It's a trope too, isn't it? The paid-up devotee inducted into the inner circle. That's how cults work, and Chris fawns on Prurience's founder Emilia Atkins, who appears, teeth gleaming, hair blow-dried, on a crappy corporate video to welcome us into her global movement. You blame her more than him – the system not the sucker.

There is, after all, a strong whiff of bullshit about the empty incantations, the confessional spirit and the artificial all-in-this-togetherness. There's Prurience merchandise and self-help CDs. The whole thing's a racket – possibly just as predatory as the porn industry it both kicks against and relies on. What, Green makes you ask, is genuine here? What's constructed?

Prurience plays with that and if, at first, the glitch from participatory event to scripted play feels like a let-down, it proves far more slippery and self-aware – much like Dennis Kelly's ‘verbatim' play Taking Care of Baby. A couple of confessions trip into stagey monologues: the old-school bore who remembers porn cinemas and snuff parties; the woman who reconciles a gay porn habit with motherhood; the gay man who just wants to lose himself in the sex he consumes. That shift is too queasy for some audience members, who, just like porn addicts, lose sight of the borders between participation and performance. It's not long before we all do, Inception-style, and that's a deeply uncertain and unsettling experience; one that gets right to the core of contemporary life. It is, Green suggests, a spin cycle of consumerism and constructed reality.

Is Prurience the solution, then? Can performance offer respite from reality – a safe space or a support group to assess it from the outside – or is it just another layer of artifice to wade through? Green leaves us hanging. As with addiction, there's no end to recovery.

Prurience runs at the Southbank Centre until 30 July