Crazyblackmuthafuckin'self, Royal Court Theatre, London

There is plenty of simulated fellatio and buggery in Crazyblack (as the box office staff call it), and not just between men. A heterosexual Jew licks a plastic replica of a large black penis, then hands it to his girlfriend so she can thrust it up his backside. The Jew – a medical student in cornrowed hair and baggy trousers who talks like Ali G – shouts: "I thought I had to act hard! Be tough! Front up! Now I know that being a true man means taking it like a woman!" Could this be the solution to the problem of rowdy, gangster-fixated black youth?

The single most important quality of good theatre is energy, and as someone who has sat through uncounted plays with all the vivacity of a dead fish on a hot day I greatly enjoyed the liveliness of Crazyblack. The author and star, DeObia Oparei, and the director, Josie Rourke, have created a very funny and often hilarious play about homosexuals, black people, and confusion of identity (though it's sometimes, as with the Jew, too absurd to be funny). There's an amusing, if obvious, send-up of "relevant" Shakespeare – some of the characters are rehearsing, in Peckham, a production of Yo'thello. As the earnest, repressed actor Raef (who can we be meant to think of?), Jo Stone-Fewings is adorable when he consents to probe his past in aid of greater "authenticity": "Mummy's left me at the school gates. She won't hug me. Toughen me up, she says.''

Laurence (Oparei), a tall, bald, muscular black man playing the Moor, spends much of the evening wearing boots and a leather jock strap for his other identity as Big Black Jungle Nigga, a character advertised on the internet. ("When I'm resting, I'm working.") Another little earner is Shaneequa, the pre-op transsexual (a wig, pink hot pants, six-inch platforms). But, to his family and friends, all these people are Femi, an African in London whose own fragmented and confused identity doesn't prevent him from – indeed, seems to qualify him for – counselling everyone else. Femi urges them, in scenes that are both hortatory and parodic, to "find your nigga!" – the secret self. With Raef this means merely learning to walk the walk – "Embrace your nigga, and you will truly dance!" – but, with the actress playing Desdemona, it involves re-enacting a childhood trauma that is improbably lurid and opportunistic. In it a 14-year-old white South African virgin forces a black boy to have intercourse with her.

It's that sort of tidiness and simplemindedness, that notion that sex is the cure for whatever ails you, that I found more distasteful than the humping and dildo-brandishing (though, I admit, it's a near thing). Despite the play's raunchiness, it is pervaded by sentimentality. Femi's brother, Olunde (Clive Wedderburn, charming as usual), is a drug dealer, but he's nice and he's funny, so he is paired off with a pretty white woman. And Femi himself finds a transvestite (droll, appealing Paul Ready) who really, truly loves him. Why? They've had great sex. In propagandising the notion that love is all and that love is easy, Crazyblack does no one of any race or sex any favours.

To 11 Jan (020-7565 5000)