Jackie Kennedy had a four-year love affair with Bobby Kennedy that began not long after JFK's assassination and grew so intense that when RFK was gunned down, it was she -- not his wife -- who instructed doctors to pull the plug, an explosive new book claims.
The married senator and father of 11 kids was the former first lady's one "true love" -- and his wife, Ethel, along with the rest of the Kennedy clan, knew about their romance, according to "Bobby and Jackie: A Love Story."
"Everybody knew about the affair. The two of them carried on like a pair of lovesick teenagers," the late Franklin Roosevelt Jr., who served as JFK's undersecretary of commerce, says in the book.
"I suspect Bobby would've liked to dump Ethel and marry Jackie, but, of course, that wasn't possible."
The book, which hits shelves this month, also includes recollections of the steamy affair from a host of other Kennedy family intimates, including Pierre Salinger, Arthur Schlesinger, Jack Newfield, Gore Vidal, Truman Capote and Morton Downey Jr.
Author C. David Heymann said he spent nearly two decades researching the tome, even digging through old FBI and Secret Service files about the clandestine couple. Tapes of his exhaustive interviews are available at the SUNY Stony Brook library.
The book's most shocking claims include:
* Six months after JFK's death, during a May 1964 dinner cruise on the presidential yacht the USS Sequoia, Bobby and Jackie "exchanged poignant glances" before disappearing below deck, leaving Ethel upstairs. "When they returned, they looked as chummy and relaxed as a pair of Cheshire cats," according to Schlesinger
* At the Kennedys' Palm Beach estate during Christmas 1964, socialite Mary Harrington saw Jackie sunbathing topless, with Bobby kneeling at her side.
"As they began to kiss, he placed one hand on her breast and the other inside of her bikini bottom," Harrington recalled.
"I was shocked. It was clear that Bobby was sleeping with his sister-in-law."
RFK later told Harrington -- who had her own affair with RFK -- he loved Ethel but "felt just as strongly about Jackie."
* When Commerce Department administrator Kenneth McKnight arrived for a late-evening meeting with Sen. Kennedy in July 1966, he found Bobby sitting on a sofa -- with Jackie "straddling his lap, her arms around his neck."
* At one point, Ethel Kennedy implored family friend Frank Moore to "tell Bobby to stop sleeping with Jackie." Instead, Moore told her to find a marriage counselor.
* Shipping tycoon Aristotle Onassis -- RFK's rival for Jackie's attention -- once threatened to "bring down" Bobby by going public with details of the affair. "I could bury that sucker," Onassis said, "although I'd lose Jackie in the process."
By all accounts, the romance between Jackie and Bobby sprang from their shared grief over the Nov. 22, 1963, assassination of John F. Kennedy.
"It was the coming together of a man and a woman as a result of his bereavement and her mental suffering at the hands of her late, lecherous husband," according to Jackie confidant Truman Capote.
"It was passionate, [but] it was doomed."
According to Gore Vidal, "The one person Jackie ever loved . . . was Robert Kennedy."
"You had to be deaf, dumb and blind not to see it," recalled Kennedy family friend Chuck Spalding, who often traveled with the pair.
Ethel -- who stayed home with the kids in Virginia -- knew about their relationship, but "evidently chose to ignore it," Heymann writes. She was confident RFK would never leave her or their family.
Still, whenever Jackie visited Bobby in Hyannis Port, "Ethel would jump up and leave the room."
By mid-1967, Jackie -- who had also been dating Onassis -- was contemplating marriage to him. She agreed to wait until after Bobby's 1968 presidential run.
RFK told Pierre Salinger, "She'll marry that man over my dead body."
On March 16, 1968, Bobby announced his bid for president. The next morning, a "morose" RFK called Jack Newfield from Jackie's apartment.
"If I had to hazard a guess," the late Post columnist recalled, "I'd say this must have been their last romantic occasion together."
On June 4, minutes after winning the California primary, Bobby was fatally shot by Sirhan Sirhan at the Ambassador Hotel in Los Angeles.
Jackie flew to his bedside -- and Ethel allowed her time alone with the dying RFK, according to the book.
Bobby was brain-dead, but a distraught Ethel refused to pull the plug, and brother Ted Kennedy was in no shape to make the call, Heymann writes.
At 1:20 a.m. June 6, 1968, Jackie Kennedy ordered the respirator shut down and signed the consent form, the book reveals.
That October, she married Onassis.