Possible Clues:

• Jackie O's son
• '60s First Son
• First editor of the magazine George
• Only non-actor ever chosen as People's Sexiest Man Alive, familiarly
• '60s White House resident, familiarly
• Celebrity killed while flying to Martha's Vineyard
• 'John-John'
• George mag founder
• Founding ed. of 'George' magazine
• Celeb often seen in supermarket tabs