WWW- The life of Hugh Hefner, the founder of Playboy magazine who presently stars on the reality series The Girls Next Door, has always been an open book. His self-promoted public persona became that of womanizer and party animal, and earned him the title of sex icon.

While we already have a clue of the kind of sexual appetite he has, seeing that he has three girlfriends on The Girls Next Door, his “authorized” biography reveals more shocking information about the 82-year-old playboy.

Steven Watts’ Mr. Playboy: Hugh Hefner and the American Dream reveals that Hefner once had a gay sex encounter, which occurred in an unspecified time and an unnamed bar in Chicago.

Hugh Hefner, who maintains that Watts’ book “is all essentially true,” said “he was propositioned [by a man] and, thought, ‘What the hell…'” He found it “an interesting experience,” though one, presumably, he didn’t choose to repeat.

On top of that, the book also details many more of Hugh Hefner’s sexual exploits, including a foursome involving his brother and sister-in-law and a porn film starring Hefner himself.

“A foursome did happen with his brother, Keith, and his wife, Rae, one evening. But while Millie, Hugh’s first wife, ultimately backed out of having sex with Keith, Hugh slept with his sister-in-law,” Watts wrote in the book.

In between tales of Hefner’s sex life, the book also tells the story of how The Girls Next Door star created the Playboy empire.

“It’s the most authoritative book ever written about me,” Hugh Hefner told the New York Post.

Mr. Playboy: Hugh Hefner and the American Dream is set for release in the United States in October.

Meanwhile, fans can relive the adventures of Hugh Hefner and his girls, Holly Madison, Kendra Wilkinson and Bridget Marquardt, by catching reruns of The Girls Next Door on E!