Last year, he launched a glossy political monthly, George, and made sure the world knew that he was its editor. Now he has taken to writing in its pages - about the Kennedys.
In next month's issue, which will be dedicated to women, New York's most talked-about editor (save, perhaps, for our own Tina Brown) wags a "you- should-know-better" finger at two of the Camelot clan for having succumbed to the temptations of the flesh, to the considerable detriment of their marriages.
Sales of the latest issue will doubtless be fueled further by an accompanying Garden-of-Eden portrait of JFK Jr, sitting cross-legged and looking longingly at an apple suspended above him. Shadows are artfully cast across the lower countours of his still-beefy torso.
The targets of his newly self-righteous pen are his cousins, the sons of the assassinated Bobby Kennedy: Joe Kennedy, a Democrat representative in Washington, and his younger brother, Michael Kennedy. The two, JFK suggests, have become America's favourite "poster boys for bad behaviour".
Both Kennedys have indeed been in the headlines recently.
Joe was pilloried by his ex-wife, Sheila, because of his efforts to have their 12-year marriage annulled by the Catholic Church. Michael was accused earlier this year of bedding his family's babysitter - beginning when she was just 14-years-old.
The pair, JFK Jr opines, stumbled by chasing "an idealised alternative to their lifestyle. One left behind an embittered wife, and another, in what looked to be a hedge against mortality, fell in love with youth".
Of the media brouhaha, he adds: "Perhaps they deserved it. Perhaps they should have known better. To whom much is given, much is expected, right?"
Sales of September's George are sure to be healthy, but if there are any beach reunions planned for the extended Kennedy family this summer, JFK Jr may want to consider staying away.
David Usborne, New York