(FORTUNE Magazine) - If Tom Perkins were a regular guy, he might have jumped at the chance to star in a reality TV show with dozens of hot twentysomethings vying for his "heart." But when the invite came, the legendary venture capitalist and co-founder of Kleiner Perkins threw it in the trash and called his romance novelist ex-wife, Danielle Steel, who persuaded him to turn the idea of appearing on a dating show into a book. Did he ever. Sex and the Single Zillionaire is everything you never expected from a distinguished 73-year-old. A saucy tale of Steven Hudson, a widowed investment banker searching for love, it showcases the highs and lows of life at the top. From Hudson's standing 5 P.M. martini, to his ne'er-do-well playboy son, to the eyebrow-raising sex scenes, it's all there. While Perkins doesn't expect rave reviews from the lit-crit crowd, his beach read will benefit a good cause (he's donating the proceeds to his biz-school alma mater, Harvard). As for the similarities between the author and his protagonist? "Pure fiction!" insists Perkins. "Steven's Bentley is black," he told FORTUNE. "Mine's silver."