First Mackenzie Phillips tells us she was keeping it in the family with her Mamas & the Papas papa, then it turns out David Letterman was mixing business with a whole lot of pleasure. Celebrity sex scandals have taken a weird turn this fall, and that's saying a lot -- it takes a heck of a gossip mag-scorcher to knock Joe America out of his cozy La-Z-boy. Still, sex scandals have been de rigeur in Hollywood since before Charlie Chaplin took that paternity test. For your curiosity, PopEater breaks down some of the most salacious moments in the Tinseltown's spotted romantic history.