Menage, By Ewan Morrison

Writing exclusively (or almost exclusively) about sex in an elegant manner used to guarantee literary immortality. The Marquis de Sade, Henry Miller, Charles Bukowski (OK, in his case, drinking and sex): they may have suffered in life but their relentless priapism paid off in the end. Now, however, few writers have what it takes to make it as proper porno-prose stars (although I have high hopes for Charlotte Roche). They can manage it for a book or two, but then the relentless bad reviews that sex writing always seems to attract scares them off and they become more self-consciously literary.

Thank goodness then for Ewan Morrison, who after a novel about swinging (Swung) and another about the importance of sex and text-sex (or sex-texts?) in long distance relationships (Distance) turns, in his latest, Ménage, to the age-old question of how to get two into one. When we last left his characters, they were tearing the seats out of their jeans to perform sexy bum-dances (whatever this may be), and this new lot are no more restrained. Ménage begins with Owen, a sometime art-critic, watching an 18 -year-old American student frig herself on a webcam while he wears the used "pink frilly girlie panties" she has FedExed him and cogitates.

As always with Morrison, his characters are psychologically damaged, although he's upped the stakes in this book, and it's clear from the first chapter that something terrible has happened between 1993 (when the back story takes place) and the present of the novel (2008). Owen is one third of the ménage a trios of the title, along with Young British Artist, Dorothy Shears, and the extravagant Saul. Art-world novels (like sex novels) are notoriously difficult to pull off, but Morrison has researched this area well, and it's easy to imagine his artist operating alongside Emin and Hirst. (Morrison is well-versed in art history and plans to work further on the connection between art and literature.) Occasionally the satire can seem just a little forced, like the man who exhibits excrement on lollipop sticks, but for the most part his aim is true.

The in-built drama of all the great ménage a trios stories (best explored, of course, in French classics such as Jules et Jim and my all-time favourite, La Maman et la Putain) is that the balance is never going to be even: someone's always going to be the pickle in the Manhattan sandwich. Morrison takes this one step further, focusing on the psychological dangers inherent in trying to sustain a fantasy. And alongside his exploration of sex, he also looks at how fame can be equally divisive, particularly among creative types. The link between art and madness is a tired theme, but Morrison makes it fresh by rooting his story in such a richly realised vision of the early nineties.

"There is nothing less sexy than sex," maintains Saul, the most controlling of the three characters. Saul is described by Morrison as "a failed artist [who] manipulated two youngsters into acting out his debased fantasies as revenge against the world that had rejected him" and although this novel is just as chock-a-block with smut as his first two, the non-sexiness of sex is Morrison's real theme.

For all his characters love of porn, dildos and cross-dressing, the actual intercourse, in this book and his others, always turns out to be a (deliberate) disappointment. It is a mark of Morrison's considerable talent that his exploration of why this is remains fascinating, and that watching his characters' fantasies (and sanity) crumble is just as interesting third time round as it's ever been before.