JRFK was involved with Monroe sexually once or at maximum twice. But there never was a love-affair. People who claim one, say that because they think that Monroe was in love with him and wanted to be treated as more than a prostitute. There is no confirmed evidence that actually this was the case. It could merely be Hollywood gossip to sell.
JFK certainly was not going to be with any women he was sleeping around with. Robert Kennedy covered his brothers scandals to protect him from impeachment and to make his 2nd term possible. He advised his brother not to be indulgent, but JFK made a mistake of assuming that he was the loved president, nothing could harm him.
Robert himself was a religious person, who did not smoke much and drank socially only. He was deeply in love with Ethel and was a devout husband. There is no evidence of him doing the same as JFK. Edgar Hoover threatened RFK into doing many things, like wiretapping Dr. King, saying he would make public his brothers sexual habits. Forced under blackmail, RFK allowed wiretap on Dr. King only for a month due to Hoover’s claims of Dr. King dealing with the communists, which Hoover extended on his own without RFK’s consent. That was Hoover’s only weapon, threat people of their personal habits and of having communist connections.
Hoover wanted same dirt on RFK, but never got anything. The only source that says RFK was at Monroe’s the night she died is that of FBI intelligence. It might sound reliable coming from the FBI, but just like many other reports that were made falsely at the time for disinformation, this report too is false to smear RFK’s image and career. RFK was with his family at his friend’s house for a vacation when Monroe died.
Once a woman called Ethel in the middle of the night saying that her marriage is over and that RFK is sleeping with her. Ethel got angry and shouted to the woman never to call her house again and that Robert is sleeping right next to her (Ethel’s) in bed.
Hence, if one checks on these facts, and chooses not to believe in fantasies and gossips, one would know for sure what RFK did and how much JFK was involved. If one dislikes the Kennedy administration or any of the Kennedys and chooses to believe in these lies just so that they can have something to say against JFK or RFK, it is their choice, but then they should know which side of the right and wrong they themselves are. Also the fact is that killing others was not the way the Kennedys did their work. They were not killers. They did not even want to commit political suicide by killing Fidel Castro. All those of allegations are merely allegations and rumours. They knew what killing Castro meant politically and even both the Kennedy brothers asked that make sure he does not die or else it will mean worse for America.
Marilyn Monroe died of an overdose. This is indeed true that her death were under mysterious circumstance and that she might have been murdered, but independent of the involvement of the Kennedys. She was going through severe personaly feelings of sufferings and loneliness as her career was going down due to her ill health. She was not able to show up in studios and was costing them in production due to which she was fired from the last movie, Something’s Gotta Give, she was working on with Dean Martin.