What a strange and unpredictable writer Howard Jacobson is. His last outing, Kalooki Nights, was a warm, baggy, digressive, multitude-containing comic novel. And he has followed it up with an introverted, sparsely populated, geometrically put-together little drama of sexual neurosis. It is as if Philip Roth (the writer to whom Jacobson is endlessly compared, and whom he resembles at his most expansive) went to bed one evening and awoke from uneasy dreams to find himself transformed into Vladimir Nabokov.

‘All husbands secretly want their wives to be unfaithful to them.’ That is the postulate picked out for the jacket copy. Is it true? Most people wouldn’t say so. I don’t expect Jacobson would say so either. But it’s what his narrator, Felix Quinn, would have us believe – and every nuance of which he explores in obsessive detail. We’re in unreliable-narrator territory here. Jacobson makes Felix’s peculiar pathology persuasive, but he does not make Felix himself persuasive.

The Act of Love – a title that at once euphemises sex, plays on the idea of artifice or feigning, and suggests, subtly, that love may be not a condition but a pattern of behaviour – is an investigation into a peculiarly perverse sort of emotional masochism.

Felix is a second-hand bookseller who loves his wife. But for Felix, love is inseparable from the fear of loss or abandonment; and having accepted abandonment as the only conclusion of love, he learns to court it. He is a votary of betrayal, a connoisseur of cuckoldry, a voyeur in his own bedroom. He is never more alive than when suspecting that Marisa is schtupping somebody else.

Marius is the third point of the triangle. He is – in Felix’s account – a near-caricatural import from Wuthering Heights: cruel of face, aloof of manner, raven of hair, given to spouting Baudelaire. When we first encounter Marius, he’s at the funeral of his mentor, an elderly don whom he was cuckolding. At the service, Marius viciously cold-shoulders his bereaved lover; Felix spots him, in fact, making an assignation among the gravestones with a pair of slightly underage girls.

When he talks to Felix his speech is Dick Van Dyke gorblimey – ‘Time of the day, squire … Nuffink to do with the weather’. Later, when he first encounters Marisa, he adopts a sort of formal archness that makes you think of a kitschy translation of Laclos: ‘I would much rather that you gave me the chance to know exactly what it is you do feel … Perhaps we could reconvene’.

It is, for both of them, love at first sight: here is a man seemingly irresistible to women, sadistic and detached. We may think: ‘prat’. But he is Felix’s dream cuckolder. And when their paths cross again, Felix goes about the task of setting him up with his wife.

There are curious weaknesses here: the plot leans, a little too much, to melodrama; and Felix is allowed to know some things that it’s hard to believe he could about the other characters and their history. But on the whole it’s an impressively sustained, and unusually intense, literary experiment.

This is a novel preoccupied with mediation. Felix’s relationship with his wife is mediated through her relationship with Marius. Marius and Felix exist in a relationship – not, Felix insists candidly at one point, of displaced homosexual longing – mediated through Marisa. And the story itself is mediated to the reader by Felix, with his foxy nudges of interpretation and his questionable reliability. ‘Words deceive’ is among Marius’s final admonishments to Felix – and the measure of this book is the extent to which that is true.

The story is also mediated to an almost comical extent by art. Felix interprets his situation and predilections in terms of Othello, David Copperfield, Sacher-Masoch, Dostoyevsky, Don Quixote, Wittgenstein, One Thousand and One Nights, the Odyssey, Electra, Molière; Marius and Marisa flirt over a portrait in the Wallace Collection, and arrange their first tryst (with Felix’s covert help) through an art-historical treasure hunt. When brought low, Felix blubbers his way through a Schubert recital at the Wigmore Hall (‘one too many cellos in it for a man reduced as I was’). Only Felix could go to a wife-swapping club (likened to Hieronymus Bosch, naturally) and run into Queequeg from Moby-Dick.

It’s the art, not the sex, that really gets Felix off. He recasts this slightly unhappy marriage, this selfish self-torture, this shabby suburban love-triangle – as the adventure of a moral exquisite. A remorselessly self-examining aesthete, he cannot see the world except by allusion; and that means that he cannot see his wife, or her lover, or himself, as they actually are. Only seldom do glimpses of a flesh-and-blood Marius, or of Marisa’s raw feelings, peep past the great distorting lens of Felix’s obsession. Felix is, finally, a sort of monster – and, as you can perhaps guess, it all ends in tears.

This novel is for the most part a fine achievement, but it’s a wintry one: more perhaps to be admired than enjoyed.