Jackie Kennedy confronted her psychiatrist about also treating Marilyn Monroe

John F. Kennedy and Marilyn Monroe's alleged affair is one of the most scandalous pieces of gossip in American history, but it could never actually be confirmed.

In fact, aside from the memorable gathering where Monroe sang "Happy Birthday, Mr. President" to John, the two only encountered each other four times between October 1961 and August 1962, according to Donald Spoto's 2001 biography of Monroe.

According to Spoto, John and Marilyn made a phone call to one of her pals from a bedroom during one of those sessions. The book also claims that Monroe acknowledged having "one" s*xual encounter with the former president soon after that call.

The relationship, according to Christopher Anderson's 2013 book "These Few Precious Days: The Final Year of Jack with Jackie," was more nuanced. He described a phone discussion between Jackie and Monroe in which the actor supposedly informed the first lady that John had made a vow. 

Jackie, according to Vanity Fair, was unaffected and said, "Marilyn, you'll marry Jack, that's great... 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.

Following her claimed relationship with John, Monroe was also said to have had an affair with his brother, Attorney General Robert F. Kennedy. Anthony Summers, the actor's biographer, apparently confirmed this with Monroe's former housekeeper, Eunice Murray.