That's what we're wondering after Anderson Cooper's appearance on The Late Show Wednesday, when he talked about his mother Gloria Vanderbilt's, ahem, frankness when discussing her love life with Cooper growing up.
"My mom has no filter," he said. "I remember watching On the Waterfront with her, and I was like, 'Did you know Marlon Brando?' And she'd be like, 'Oh, yes.' "
In her time, Vanderbilt, who turned 90 this year, was also linked to Clark Gable and Frank Sinatra, as well as a host of others detailed in her 2004 memoir It Seemed Important at the Time, excerpts from which we suspect young Anderson was not subjected to.
Check out the full clip of the interview below.