The pleasure of Paul Bailey's work is there from the opening page, in this and all his novels.

A writer whose tone is like a long, cool drink on a sweaty day, he has a wit, detachment, and clarity that allow him to explore subjects that in less able hands might descend into the maudlin or sentimental.

Neither word is applicable to The Prince's Boy, even though the heat of this story is a love affair that has lasted half a century and more, long after one lover is dead. As Bailey demonstrates, it is possible to describe passion, and unswerving attachment, with an honesty that makes the fictional feel true. As indeed it surely is.

Written towards the end of the narrator Dinu Grigorescu's life, he tells us: "It is love I am writing about here, in this memoir of a life half-lived." His story begins in 1927 when, as a wealthy Romanian businessman's son, he is allowed a few months in Paris, to write a novel and discover the world. Aged 19, Dinu discovers first Proust and then a man he will love forever, and the two remain guiding stars for the rest of his days.

Naive and unworldly, Dinu is a little drunk when he makes his way to a male brothel, whose owner is Albert Le Cuziat, a man immortalised by Proust as Jupien, the tailor turned brothel keeper, who encourages his gigolos "to be more vicious". The Proust connection deepens when Dinu is ushered into the presence of Razvan, a handsome Romanian who has twice met the great author. One hour later, Dinu has lost his innocence, and his heart.

Described by Albert as a "noble savage", Razvan has a peculiar history, having been adopted as a boy by a prince, who later died in tragic circumstances. Razvan is left confused, an educated sophisticate whose roots are among the peasantry. This tension, which he never resolves, begins to gnaw at him.

What follows is a story of growing up. It was dangerous in that era for Dinu to return to Bucharest and declare himself homosexual, but eventually that is what he does. As Romania and Dinu's hard-bitten father slide into fascism, Dinu - now an academic - escapes to Paris, where he and Razvan set up home. For taking that previously unthinkable step, he wryly admits: "I have to thank history". The catalyst was the appearance one night at the opera in Bucharest of men in green shirts.

"They signalled membership of the Iron Guard, a political party led by a fanatic named Codreanu, who had been inspired by St Michael no less, to protect and preserve the purity of the Romanian people. Purity? What purity? The Romans conquered and occupied Dacia, and then the Greeks, the Turks, the Slavs, the Hungarians and the Germans occupied our land, planting their semen wherever they desired."

Anger so clearly expressed is rare in this work, Dinu's voice usually being one of reflective sorrow and tempered observation. Menace hovers in the wings, both for the lovers' future, and for Europe's. Nearly 20 years Dinu's senior, Razvan is middle-aged when they settle together, and drinking more heavily than ever. His melancholy grows, and with it Dinu's anxiety, but their love prevails: "I was as happy as I could be with a deeply unhappy man," he says.

As their woes deepen, Bailey draws the picture of the Nazis' advance, the eager collusion of Dinu's family, and the gradual tightening of Hitler's hands around Romania's willing neck. He now recognises his stepmother, an incorrigible flibbertigibbet, as "one of the few sane people in Bucharest society". She is a welcome antidote to Dinu's profoundly religious mother, who died when he was a boy and still haunts his dreams and his conscience.

Rich in character studies, yet so delicately written one barely registers at first its many layers and nuances, The Prince's Boy is a winterly evocation of a grief and love that will not wither. Meanwhile, around this unmovable core he evokes the sinister merry-go-round of human affairs, of the venal and the vicious and the merely vain. Tender and profoundly touching, this is a novel whose almost dry manner could lure the reader into thinking the author has no designs on you. By its end, however, his fingers have squeezed your heart.