Regrets Only<i> by Sally Quinn (Simon & Schuster: $18.95; 556 pp.) </i>

“Whew!”

That’s the sound of Washington issuing a collective sigh of relief. Former Washington Post writer Sally Quinn might know all the hot insider secrets--but her novel, “Regrets Only,” keeps them tucked safely under the sheets.

This is Washington, where lust and power meet--or at least get seated together at dinner parties. Only trouble is that it’s a Washington sanitized enough to get OK’d by the Meese Commission on Pornography. Welcome to Playdough Politics and Safety-Scissors Sex.

“He reached an arm over and grasped one of her arms, brusquely pulling her down on the sofa under him, then pressing his heaviness upon her, knocking the air out of her so that she thought she would faint.”

Faint? What does the First Lady know of fainting? By Page 419, when the alleged seduction takes place, we, the readers, are the ones passing out, weakened as we are by an onslaught of federal-budget prose. “Regrets Only” is like Washington in August.

At the center of this power-and-politics tale: the amazing, beautiful, blond-and-talented reporter, Allison (Sonny) Sterling. Sonny happens to be the godchild of the President of the United States. She also just happens to be “The most successful and glamorous reporter in Washington . . . indispensable . . . a consummate professional; cool, fast, thorough, tough . . . She was the best.”

Of course. But Sonny falls into that old professional-competent-woman trap. Instead of running the country, she should have been listening to country music. Then she would have known to “Stand by Your Man.”

Hey, and what a guy! Flamboyant and aggressive, Desmond Shaw, Washington bureau chief of a weekly newsmagazine, drinks Irish whisky neat, calls his lovers “babe” and “sweetheart” and tells a favorite she is “one hell of a woman.” Shaw, who seems to be trying to be journalism’s Clark Gable, comes off more like its Fred MacMurray.

Des does manage to sound the novel’s most important warning. He tells the Second Lady an anecdote about a reporter who seemed to like his subject, then wrote a devastating story. The punch line: “I like ‘em all till I sit down at the typewriter.”

Readers have been fair-warned. There is no one in this novel to like or even feel sympathy for. There were moments when I hoped that Desmond Shaw would wind up not with the Sadie-the-First-Lady or with sexy Sonny, but with the President. Anything for a thrill.

Thrills used to be Quinn’s stock and trade. What really is regrettable about “Regrets Only” is that Quinn’s by-line once guaranteed a good fat slice of the overripe apple that is Washington and its social scene. With salon swiftness, she could cajole the tastiest morsels out of the most tasteful people. This is an art, and she was the master of it.

Quinn practiced judo journalism, using her subjects’ own power against them. And some of that vintage Quinn is here. But the traces of her wit, her Bitter Lemon bite, are in the end only traces. They pass by too quickly, like good hors d’oeuvres at a bad party. Mmmm, tasty--but couldn’t we have spent the evening doing something else?

If the main course is lacking, Quinn’s condiments are nonetheless to relish. What are all those people we keep electing doing in Washington? When not trying to legislate or lead, they are partying--a carefully calibrated social whirl of guest lists and Byzantine protocol that make the back-home climbers seem very junior league.

“And you must understand,” the new First Lady tells her press secretary, “even though this kind of thing may seem frivolous to you, that international relations are at stake. A tacky table decoration would be noticed by the wife of the Brazilian President, who would point out to her husband that he had been demeaned by the President of the United States.”

Frivolous? Yes, of course, but “Please, sir, may I have some more?” More backstairs, more back-stabbing, for it is in writing about this tarnished glitz that Quinn herself shines. She knows these famous folks and their infamous folkways, and it is a shame she lets a ponderous, preposterous plot get in the way of the dishy tidbits.

And the dialogue. They can’t talk like that back there, can they? Not unless they have all been taking instructions from a subcomittee of the Romance Writers of America.

“I’ve made love to you,” Shaw tells Sadie. “I can always tell a woman’s politics by the way she makes love.”

Or, perhaps, by the way she writes a novel.