Spectre of female Casanova whose novels shocked Britain raised after her son’s death

The book’s content set pulses racing while nude scenes in an equally popular spin-off TV mini-series also shocked viewers.

Both depicted the antics of an extended dysfunctional family, whose passions were liberated by war and their unconventional love affairs.

It caused surprise at the time to learn the author was in her 70s but only after Wesley’s death in 2002 did it emerge that the colourful nature of her fiction was nothing compared with her own sex life.

Known as Wild Mary she was a party animal who had numerous lovers and three sons by three different men.

Her second born was literary agent Toby Eady, whose death last month from cancer aged 76 has put his mother back in the spotlight.

Like her fictional characters Wesley, who sold three million books, regarded wartime as an opportunity to make hay.

She once remarked: “War freed us. We felt if we didn’t do it now we might never get another chance.

“It got to the state where one woke up in the morning, reached across the pillow and thought, ‘Let’s see, who is it this time?’ Too many lovers, too much to drink.”

Wesley had an unusual method of getting to sleep. Instead of counting sheep she would mentally recite the names of her many lovers… or at least the ones she could remember.

We know this because in the months leading up to her demise aged 90 Wesley laid bare her love life to her biographer Patrick Marnham, along with revealing personal letters, on the understanding that his account would be published posthumously.

The subsequent revelations about her promiscuity threatened to overshadow her literary achievements, including 10 bestsellers in the last 20 years of her life.

Wesley was born Mary Farmar in Berkshire in 1912, the daughter of a wealthy army colonel. Her mother Violet struggled to keep her in check and, after discovering Wesley in bed with Lord Baden Powell’s son, packed her off to relatives in India.

In 1937, to appease her family, Wesley married Charles Eady, second Baron Swinfen, but they were ill-matched not least because the stuffy aristocrat did not share her enthusiasm for sex.

They had a son Roger but the outbreak of war was the signal for Wesley to really let her hair down.

By then she was working for the War Office as a code breaker and living away from her husband and son.

She was a great beauty and, wearing a mink cape, she and a female friend would hunt for men at the Ritz hotel in London.

There were many lovers and one fling with a Czech airman produced another child, Toby, who was accepted by Lord Swinfen as his own. Wesley said of the war: “It created an atmosphere of terror and exhilaration and parties, parties, parties.”

Shortly before the end of the conflict Wesley met a married man, Oxford-educated playwright and journalist Eric Siepmann, who was nine years her senior.

The pair exchanged explicit letters and conducted their affair in hotel rooms. They eventually tied the knot in 1952, had a son William and settled in Devon after a spell in Berlin.

There was a period of stability but Siepmann was a heavy drinker who was occasionally violent towards his wife. He committed suicide in 1969, leaving Wesley at a crossroads in her life.

For all his shortcomings she had been devoted to Eric and fell into a trough of depression, which lasted many years.

Making matters worse there were financial problems and Wesley became near-destitute in her late-50s.

Her career finally bloomed at the age of 70 when her first novel was published: Jumping The Queue, the story of a woman who cannot bear to go on living after her husband’s suicide.

Readers loved her style which was a mix of quirky, sad and funny.

Beneath the comedy of manners always lurked a darker side, however, including incest and illegitimacy among the upper middle classes. Asked about the sex in her books she insisted that the young did not have a monopoly on the matter.

The Camomile Lawn, published in 1984 when she was 72, was her greatest success. Set in Cornwall during the Second World War it told the interwoven stories of three families and was peppered with the F-word.

Despite being in her 70s Wesley embarked on an affair with Robert Bolt, the Oscar-winning screenwriter of Dr Zhivago and A Man For All Seasons, who was 12 years younger.

He was keen to marry but she refused stating: “There are men you want in your bed but you don’t want in your head.”

Then in the 1990s, when she was 84 and still at the peak of her powers, Wesley suddenly stopped writing novels, explaining that she simply felt she had nothing left to say.

She spent her final months, while suffering from cancer, telling her extraordinary life story to her biographer.

Her only regret, she said, was that she was too sick to invite him into her bed.

Right up until the end Mary Wesley had the ability to shock.