Mother and son Gloria Vanderbilt and Anderson Cooper look as close as they come during their at-home interview with PEOPLE‘s Jess Cagle, but Cooper made clear that some things are better left unsaid.
The 48-year-old CNN anchor was taken aback when the heiress, 92, when asked what she could talk about all day, and for hours on end, answered “sex.”
Cooper grew red, prompting Cagle to joke if that was his answer, too.
“I’m not going to say that in front of my mom,” he laughed. “No matter how weird our relationship is.”
Vanderbilt turned to her son, saying sweetly, “Sweetheart, don’t edit yourself.”
It was a tender moment in an expectedly tender interview, in anticipation of their new memoir, The Rainbow Comes and Goes: A Mother and Son Talk About Life, Love, and Loss, which hits shelves on Tuesday.
Watch the clip, below: