You really seem to be hung up over the fact that JFK (and RFK, as well) screwed Marilyn Monroe. Hell, approximately 33% of the male population of Hollywood had already done that (the others were all gay). Also, you seem to imply that Jackie and Marilyn were the ONLY women he screwed around with- very, very far from the truth. Any of the Kennedy brothers would go for the hole in a rolling doughnut- then brag about their "conquest" later. This is well-documented, and there were lots of ugly women who just happened to be around when JFK needed some "physical therapy".
(I personally think that this satyriasis was caused by his amphetamine use- it's what we had before VIAGRA was invented...) Personally, I would have stuck with Jackie- he was the only good thing about his miserable Administration.
The Kennedys sexuality was pretty strange by most standards.
Old Joe would compete with his sons - and at the same time they all claimed they were Catholic.
I remember once some friend commented on Dean Martin's sexual capers. "Dean wasn't like you and I. Women would throw themselves at him." That's how it was for JFK.
He certainly did have taste - although he didn't always exercise it. That's to his credit - since so many have no taste whatever.
I didn't really care about his sexuality - until it began to interfere with his ability to govern as it did with Clinton. Sexual adventures seem to be a normal part of the lives of many men - and especially powerful men. That's how it is.