REDBACK By Howard Jacobson Viking. 314 pp. $17.95

Even if you haven't read them, you can get some notion of British novelist Howard Jacobson's literary predilections from the titles of his first two novels: "Coming From Behind" and "Peeping Tom." But where those two were merely wonderfully sexy, clever and funny, his new novel, "Redback," is leeringly, heavy-breathingly sexy; dazzlingly, brilliantly clever; and side-splittingly, knee-slappingly funny.

(For readers who automatically mistrust such enthusiasm from a reviewer, especially in the matter of humor, which, after all, is very personal, permit me to say, alternatively, that "Redback" is indeed very, very funny, with a wit whose universality truly transcends national boundaries.)

This time, Jacobson is writing in the voice of Karl Leon Forelock, native resident of Partington, Britain's dreariest town, who escaped thence to Cambridge, where he took a double-starred first in Moral Decencies. Almost inevitably, it seems, this achievement wins the attention of the CIA, masquerading as something called Freedom Academy International, in the person of a priest named Dinmont Manifest, an academic operative who operates pretty well. Even so, Forelock explains, the CIA was especially interested because "I was the only undergraduate in Cambridge who wasn't a homosexual.

"In those days homosexuals were always referred to as practising. You could tell just by looking at me that I'd had no practice whatsoever."

After the frustrated longings of Cambridge, where he affected the manner of a man "you could trust with your property but not with your sister," the offer of a hush-hush, all-reasonable-living-expenses-paid residence in Australia is irresistible. His job: to tutor Australian spies-in-training in proper moral attitudes. His mission: to insinuate himself into academic and political society with a view toward quashing anything (books, films, radical literature and so on) that threatens old-fashioned conservative values. None of it presents a problem for this double-starred graduate in Moral Decencies, so long as someone else is paying his rent.

Met at the pier by an academic party ("nervous and yet aggressive, introverted and yet histrionic, gauche, grey, ghostly, and cataleptic"), he finds himself within hours at a party where all the wives are named Robin, Robyn or Robinne, and spend their time drinking Pimm's and serving boeuf bourgignon. Before very long, he's in the thick of it, deeply involved with organizations like CACA (Campaign for A Cleaner Australia) and BOONG (Bureau for the Obtainment of Overseas News and Gossip), and people who are busy "getting on with leftists and rightists, reconciling unilateralists to multibelligerents, explaining russophiles to sinophobes," and others who, though profoundly political, have a hard time distinguishing between Djakarta and Djamaica.

Then there's the matter of his private life -- well, all right, his sex life -- with, most notably, Venie and Maroochi, Australia's foremost team of synchronized swimmers, who also boast many other talents, ("Do you know, those girls taught me how to tell Bach's sons apart"), but let's not try to sort out that particular tangle here.

And, of course, there's the painful matter of the eponymous redback, near cousin of the tarantula, which administers a particularly Australian and debilitating sting to the very locus of Forelock's manhood, a violation that wonderfully refocuses his views of womanhood, Australia, himself and life in general.

There's hardly a functionary, a fop, a foible or a folly that escapes Forelock's comment -- invariably phrased with a kind of stunned solemnity -- or author Jacobson's barbarous but charming wit. A certain amount of humor comes from the Briton's apparently ingrained inability to take anything or anyone Australian with great seriousness, whether it's Rolf Harris, Patrick White, Clive James or animals designed with convenient pockets. But Jacobson's ultimate targets are really all those people about whom we can not say: They know who they are. The result is a book that revels in jokes and japes. Revels? It positively writhes with them.

The reviewer is a journalist, travel writer and novelist.