Here are some of old Hollywood's most scandalous secrets. 

Number one, when he was nine years old, Cary Grant's mother disappeared. At first, his father told him that she'd gone to a seaside resort, but then later switched his story and claimed that she died. Grant believed this until he heard his father's horrifying deathbed confession. His mother was still alive, locked up in a lunatic asylum.  

Number two, Anthony Perkins shared a passionate romance with Hollywood heartthrob, Tab Hunter. They kept their affair a secret from everybody, and to their friends, they were always just good college buddies. 

Number three, Kim Novak and Sammy Davis Jr. fell hopelessly in love, but the prejudices of the time destroyed them.  When producer Harry Cohn discovered them, he hired the mob to threaten Davis, ultimately forcing him to marry another woman. 

Number four, Richard Burton wrote more than 40 poignant love letters to Elizabeth Taylor, even though he was married to another woman. However, she didn't receive his last letter until after he'd already died, and she took that secret to her grave. She refused to reveal its exact contents, slept with it next to her bed, and was eventually buried with it.