For several years, British society had buzzed with gossip about Lady Antonia Fraser's roving eye. The columnists, limited by fierce libel laws, could publish only timorous items about her "good friends." But reporters sent juicy anecdotes under pseudonyms to Britain's scandal sheet Private Eye, which began to refer to the smashing 42-year-old author as "Lady Magnesia Free-love." Even her own sister, Lady Rachel Billington, wrote a novel, Beautiful, which is an apparent tattle about Antonia. The book's heroine is in her late 30s and described as "beautiful and admired and loved by her husband, children, friends and a patient queue of lovers."

And so when the scandal broke full-panoplied about Antonia's blond head two weeks ago, social and literary London clucked appreciatively at the spectacle of a much envied lady getting hers. As Britain's biographer of royalty, she once disclosed that she wept while writing the execution scene for her best-selling Mary Queen of Scots. The tears may have been the first evidence of a self-fulfilling prophecy. In Lady A's own saga, the ax has been wielded by a scorned wife rather than a stern queen—actress Vivien Merchant, 46. Her suit for divorce from her famed playwright husband of 19 years, Harold Pinter, 44, has named Lady Antonia as co-respondent.

Merchant was steaming. She invited a Daily Express reporter and photographer into her home, sipped small whiskeys, changed into a crepe dress and new makeup for pictures and commented, "Antonia collects men like others smoke cigarettes." She said she had known about the affair since March but would have been willing to forgive and forget if it had not continued beyond the usual three-month limit to Lady A's previous friendships.

"It seems he is possessed by Lady Antonia," Merchant said of her husband. "She has cast a spell over him. How she can do it with six children to look after, I don't know." Her accusations had the unintended but unavoidable effect of politically embarrassing Lady Antonia's husband, the Conservative and Roman Catholic MP, Hugh Fraser, 57—whom everyone agrees is "a saint."

In pre-scandal days on the telly, where she appeared with irritating frequency, Lady Antonia portrayed herself as dazzling wife, devoted mother, and doting daughter of the Earl of Longford, dubbed "Lord Porn" for his attacks on smut in the British Isles. As a result of these posturings, Lady Antonia has become fair game indeed.

Even her literary credentials are under scrutiny. It is being said that she employs researchers to help assemble facts for her books, nannies to tend her children and a cook to boil the mutton—belying the woman tirelessly working as wife, mother and historian.

While the furor continues, Hugh Fraser has maintained a dignified silence, although political pressure on him to leave Parliament or renounce his wife is growing. Pinter has wisely gone underground while Merchant markets her wrath. As for Lady Antonia, London is awash with rumors about her. One has her and Pinter determined to marry. Another concerns her mother, the Countess of Longford, Roman Catholic convert and distinguished biographer (Queen Victoria). She is said to have told her eldest daughter she might as well have a good time while she is young.