THE SEXIEST MAN: HIS STORY

By GINIA BELLAFANTE

The wedding to Daryl Hannah still hasn't happened, so those whose appetite has been whetted for a huge helping of JOHN-F.-KENNEDY-JR.-abilia must look elsewhere. Luckily, a new book should tide them over. In her unauthorized biography, Prince Charming, British journalist Wendy Leigh, who wrote a notorious book about John's cousin-in-law Arnold, chronicles the life of the man whom the gods have denied nothing. We learn that he crawled through fish guts in a fraternity initiation, that his mother threatened to disinherit him when he considered a career as an actor, that he lunched with Julia Roberts and slept with Madonna (that relationship didn't work out, we're told, because ''Madonna came on far too strong for him. Blatant sexuality really embarrasses John''). According to the book, he flamed out with famous flirt Sinead O'Connor. When John asked for her phone number, the singer snapped his pen in two.