Manwatching, Edinburgh Fringe: a monologue about female sexual fantasies, delivered by a male stand-up

It is 10.30pm on a Monday evening and comedian Nish Kumar is standing on a brightly lit round stage, waiting to be given his script. “I am neither an actor, nor a woman,” he informs the audience.

An odd thing to say, perhaps, but he is about to perform, Manwatching, an hour-long monologue about female sexuality - specifically the sexual history, desires, fantasies, anxieties, secrets and peccadilloes of one female playwright. Kumar has never seen the script and he has no idea who wrote it. Nor does the audience. The writer is anonymous and stipulates only these things: that her monologue is performed by a male comedian, and that he is given no time to rehearse.

The piece was first workshopped at Mach Comedy Festival in May, when Tim Key was the reader. Now it is has arrived at the Edinburgh Fringe, in a Paines Plough production in association with the Royal Court Theatre. James Acaster, Nick Helm and Marcus Brigstocke are set to perform it over the course of the month. A London run is likely to follow.

“I thought, who better to give the words of a woman desiring men to, than the voice of a man, as it's so much more comfortable and familiar for us to hear about desire through the male perspective?” explains the playwright. She decided to remain anonymous as she did not want to become known as a sex writer.

”I'm not a person who writes about sex in my regular life. I look at many different topics and I didn't want this to overshadow that," she says. ”It also felt like the right choice to make it universal and accessible." Her husband is aware that she has written the piece but has not yet seen it. "Nor do we have any plans for him to see it. Some things should remain mysterious."

The piece is frank, funny and often explicit - perfect fodder for a stand-up, in some ways. But it also skewers its male performer, forcing him to adopt the female voice as he lists the writer's ideal male qualities and outlines in some detail her teenage sexual awakening and her fears of becoming old and invisible, or “Photoshopped out of the frame.” It ambushes him with passages on the joys of masturbation, her darkest sexual fantasies, even commentary on his own looks.

It's an hour-long heckle, if you like. “I wanted to subject a male performer to the same objectification that women go through,” agrees the playwright. “The success of the piece shows have far we haven't come in a way. If it was the other way round, it would feel like an act of violence.”

Kumar did a terrific job on opening night, giving an intelligent witty reading. Did his comic timing help? “I found myself falling into the rhythms of my stand-up under pressure. It's a survival instinct, a comfort blanket.”

A slick, studied stand-up, Kumar is cuurently performing his own hour-long show daily at the Pleasance Courtyard (7.15pm). Delivering an unseen script was an exhilarating “shift of gears,” he says.

“I enjoyed the feeling of powerlessness. As a stand-up you're constantly trying to assert your authority over the audience, constantly fighting for power. I felt connected to the audience because none of us knew what was about to happen. I felt like an audience member who has been called up on stage in a Derren Brown show. Your safety is in someone else's hands.”

Manwatching, 14, 21 August at 10am, 15, 19 August at 10.30pm, Roundabout @ Summerhall (0131 560 1581; www.edfringe.com)