Revealed: Marilyn called Jackie to confess JFK affair... and First Lady replied 'that's great, I'll move out and you have all the problems' 

• 'These Few Precious Days: The Final Year of Jack with Jackie' claims the First Lady 'knew everything' about JFK's cheating
• But his relationship with Marilyn Monroe 'seemed to bother her the most'
• The book also reveals JFK's alleged dependence on drugs administered by his physician nicknamed 'Dr Feelgood'

Marilyn Monroe called Jackie Kennedy at the White House and confessed she was having an affair with her husband, to which the First Lady responded 'that's great... I'll move out and you'll have all the problems,' according to an explosive new book.

In 'These Few Precious Days: The Final Year of Jack with Jackie,' author Christopher Andersen claims Jackie 'knew everything' about Jack's cheating and turned a blind eye, but his relationship with Marilyn 'seemed to bother her the most.'

And she was right to fear the bombshell actress, because Marilyn's sights were firmly set on becoming the President's second wife.

Affair: A new book claims Marilyn Monroe, pictured with JFK, called Jackie Kennedy and confessed she was sleeping with the President

Marilyn, who long grappled with psychiatric and emotional problems as well as drugs and alcohol, was convinced JFK was about to leave Jackie for her, her friend Jeanne Carmen reportedly revealed.

'Can't you just see me,' she asked Carmen, 'as first lady?'

According to excerpts of the book, published by The New York Post today, Peter Lawford claimed Marilyn called Jackie and told her she was sleeping with Jack, and that he'd allegedly promised to leave his family for her.

'Marilyn, you'll marry Jack, that's great,' Jackie responded, according to the account. 'And you'll move into the White House and you'll assume the responsibilities of first lady, and I'll move out and you'll have all the problems.'

Revelations: The revelations are contained in the explosive book 'These Few Precious Days,' pictured