Across the world, the story is the same. Sex scandal. Media frenzy. Another prominent man caught with his pants down. So, why do men take such risks for sex?Bettina Arndt's new book, What Men Want - in bed, is all about why sex matters so much to men. More than 150, mostly older, men kept diaries for her, talking about what it is like to live with that constant sparking sexual energy.