Jackie Onassis Kennedy stares lovingly at her husband John F KennedyNPR / Richard Avedon

For a time during her reported affair with John F. Kennedy screen goddess Marilyn Monroe, who suffered periodically from drug addiction and mental illness, fantasized about becoming the First Lady.

But first she'd have to face down the real one. In 'These Few Precious Days: The Final Year of Jack with Jackie', author Christopher Andersen describes how Monroe decided to call Jackie Kennedy and inform her that she was having an affair with her husband.

The First Lady had an answer the bombshell didn't expect: 'That's great, I'll move out and you have all the problems,' Kennedy scoffed.

According to the Business Standard, Andersen's book describes how the First Lady normally turned a blind eye to JFK's cavorting, but his relationship with Monroe was the last straw.

According to the book, Monroe seriously believed the President was going to leave his wife and marry her, even going so far as reportedly telling her friend Jeanne Carmen 'Can't you just see me as First Lady?'

At thirty-six Monroe realized her sex symbol days were numbered the role of second wife of the president became increasingly attractive. But the First Lady, although dismayed by the clandestine relationship, was more than a match for Monroe's ambitions.

The new book also claims the President took regular amphetamine and steroid injections, administered by a man he nicknamed Doctor Feelgood.

Andersen claims the President took high-dosage shots around four times a week, at a level that was believed to have concerned his doctors due to the cocktail of medication he was already on to combat other health concerns.

Despite her misgivings about becoming First Lady, Jackie Kennedy was startled to discover the White House was the place where she and Jack came closest to fulfilling her cherished dream of a happy marriage.

'I said to myself, ‘It will be such a goldfish bowl. With the Secret Service and everybody here, I’ll never see my husband. It will ruin our marriage.'

But the opposite happened. 'I remember thinking, 'What was the matter with me?' It was when we were the closest,' she said. 'I hadn’t realized the physical closeness of having his office in the same building and seeing him so many times a day.'

'It was,' Jackie said, 'the happiest time of my life.'

Like Jack, Jackie along with most members of her generation and her class viewed displays of affection in public places as gauche.

'Jackie was a very self-contained person, especially in the White House,' said Kennedy family photographer and close friend Jacques Lowe. 'She very much lived her own life, as much as she was allowed to. Jack certainly wasn’t jumping into bed with her every night. But when they were both there, they made time for each other.'

But not everyone thought their marriage one of political convenience. 'If he was capable of loving any woman, and I believe he was,' said broadcast journalist Nancy Dickerson, who once dated Jack, 'that woman was Jackie.'