By Louise Lague
February 20, 1984 12:00 PM

With the publication a year ago of Heartburn, Nora Ephron’s painfully funny novel about a writer who leaves her husband for fooling around with another woman, everyone thought the case was closed on I’affaire Jay. After all, the best-seller was a thinly disguised snippet based on Ephron’s own sudden split from Watergate wunderkind Carl Bernstein, whose affair with Margaret Jay, wife of Peter Jay, former ambassador from Great Britain, was publicly revealed in 1979, just after Ephron had delivered the second Bernstein baby boy.

Alas, now there’s a new twist in the age-old plot. Even as Bernstein and Margaret Jay were partying publicly in the nation’s capital, it turns out, Peter himself was enjoying the affections of the Jay family nanny. Jane Tustian, 33, who finally sought release from the Jay household (which no longer includes Margaret) in September, is now demanding child support for her 3-year-old son, Nicholas, who, she claims, was fathered by Peter Jay. The ex-diplomat has admitted he may well be Nicholas’ daddy, but so may the Jays’ chauffeur at the time, Tustian’s then boyfriend Jim Patton, now living in Canada.

Pending blood tests of both men, Jay is sending Jane Tustian some $55 a week and has agreed to support the child if he turns out to be the real father. At any rate, as Jay’s lawyers concede, “Jay will still wish to take a benevolent interest in [Nicholas’] future, as he is fond of the child.”

That is understandable. Though the passion apparently cooled several years ago, Nicholas has been raised in the Jay household. But in September, when sometime actress Lizzie Spender, daughter of British poet Stephen Spender, moved in with Jay, Tustian took Nicholas and has recently moved into low-income public housing. “I have kept silent until now,” Tustian told a London paper, “because I was happy to be his housekeeper. Nicholas and I were fed, clothed and had a roof over our heads. I’m making this public because I can’t support myself.”

Peter and Margaret have never been a low-profile couple. She is the daughter of former Labor Party leader James Callaghan who, upon becoming Prime Minister in 1977, raised eyebrows by sending his son-in-law to Washington as British ambassador. There the Jays became the talk of the town. She was 37 and a former BBC producer; he was just 40 and had been economics editor at the London Times. Tustian, then 26, had already been with them for five years, tending their children, Tamsin, 12, Alice, 9, and Patrick, 5. Bright and attractive, the elder Jays were considered “quite a dinner party catch,” says one Washingtonian. “And instead of having a lot of stuffy diplomatic types around, they had a lot of journalists.” One such elbow rubber was Carl Bernstein, still riding the Watergate wave and still married to Nora Ephron.

After Margaret Thatcher’s election as British P.M. in 1979, Peter Jay resigned as ambassador but stayed on in Washington with Margaret, renting a house in D.C.’s fashionable Kalorama district. Peter researched a book at the Brookings Institution while Margaret worked as a consultant for National Public Radio. Carl and Margaret went around together until the late Washington Star’s Ear column revealed their romance. Nora moved to New York with 17-month-old Jacob and newborn Max and later filed for divorce.

In August of 1980 Tustian gave birth to Nicholas in Washington, claiming that he was the chauffeur’s son. That same year the Jays more or less separated, with Peter flying alone to London to launch a morning variety news show. The following summer Margaret, the children and nanny Jane went back to England too, Tustian and the children reportedly moving in with Peter, and Margaret living elsewhere.

Margaret, now a reporter for the BBC investigative show Panorama, made frequent trips to the U.S. to visit Bernstein. But by last year the two had drifted apart, and Margaret and Peter are still legally married. Bernstein has since moved down from ABC News Washington Bureau Chief to reporter (though at an estimated annual salary of $150,000), and this past summer was arrested for drunk driving. Shortly after, he checked into a D.C. hospital for a week to be treated for “severe tension headaches,” according to his doctor.

“It’s just awful that their lives have taken this scandal-sheet turn,” says a Washington friend of the Jays. “It’s all so tawdry.” Adds another D.C. acquaintance, “Theirs was an English marriage. It was just understood that one had affairs. It didn’t mean that you weren’t fond of one another.”