Anderson Cooper and his mother, Gloria Vanderbilt, have a very close and honest relationship as they describe in their new book, but the 92-year-old recently shocked her son with one secret he did not know about.

During an interview on March 30 with Jess Cagle about their upcoming memoir The Rainbow Comes and Goes: A Mother and Son On Life, Love, and Loss, Vanderbilt made the admission.

"I, myself, when I went to Farmington [boarding school in Connecticut], I went through a brief so-called lesbian relationship with a girl in school," she said as Cooper sat next to her looking stunned.

“What? Hello … This is news to me,” the CNN anchor told Cagle as his mother continued with her story. Anderson then joked with Vanderbilt, saying that she didn’t mention a lesbian romance in their book.

Anderson came out publicly as a gay man in 2012. His mother’s understanding of homosexuality was formed by her own mother, who in 1932 was “accused” of being a lesbian.

“That was very difficult for me growing up to try to figure it out,” Vanderbilt revealed. However, she added that she later learned, “It has nothing to do with whether it’s two men or two women, it’s love. And it’s just like being married, it’s what it is.”