You generally can’t get much by news reporter Anderson Cooper; unless, of course, you’re his mother, fashion designer and artist Gloria Vanderbilt. Gloria and Anderson are releasing both a documentary on Gloria’s life, Nothing Left Unsaid, and a memoir,The Rainbow Comes and Goes. The two recently sat down with Jess Cagle from People and Entertainment Weekly for a promotional interview. People is parsing the interview out, as they typically do. During the interview, Gloria, 92, dropped a bit of a bombshell on everyone, including her son. She divulged that she had had a lesbian relationship at the age of 13 with another girl at her boarding school named Cynthia.

For anyone unfamiliar with Gloria’s life, she was the center of a contentious custody battle, after her father’s death, between her mother, Gloria Morgan Vanderbilt and her paternal aunt, Gertrude Vanderbilt Whitney. In an attempt to prove Gloria’s mother was negligent, her aunt “accused” Gloria’s mother of being a lesbian. At the time of the trial, 1934, this accusation was such that the press was not even permitted to write about it. Thus, Gloria spent most of her life believing that a lesbian relationship was damning enough to lose your own child.

Anderson Cooper and Gloria Vanderbilt have written a book together and they are the subjects of an upcoming documentary, but there are still things the mother-son duo don’t know about each other.

In a recent interview with PEOPLE and Entertainment Weekly editorial director Jess Cagle, Cooper, 48, learned that his mother, 92, was once in a same-sex relationship.

“I, myself, when I went to [Miss Porter’s School in] Farmington, [Connecticut] I went through a brief so-called lesbian relationship with a girl in school,” Vanderbilt revealed after Cooper discussed coming out to the author.

In response, the CNN anchor appeared shocked, saying, “What? Hello,” and adding, “this is news to me. You didn’t mention this in the book, Mom.”

“Cynthia, her name was, and she came once to visit my aunt in New York on holiday,” continued Vanderbilt. “We had this sort of lesbian relationship and it felt so great. It felt so good and yet I thought, ‘There’s something about this,’ and this is before the thing I knew about my mother. I thought, ‘No, this is something that’s not really what I want.’ It was very brief.”

Vanderbilt said her understanding of homosexuality was largely shaped by the public gossip surrounding her own mother, Gloria Morgan Vanderbilt. Cooper, who came out as gay in 2012, explained that during a 1932 custody trial Gloria Morgan Vanderbilt was “accused” of being a lesbian.

“That word wasn’t spoken. The press wasn’t supposed to write about it,” Cooper said. “My mom knew that something terrible had come out in the court, but she didn’t know what it was and she didn’t know what being a lesbian meant at the time, obviously.”

[From People]

I must emphasize how huge the custody trial over Gloria was. Because of the subjects – the American dynasties Vanderbilts and Whitneys – the press was all over it. Gloria had a $2.5 million trust to be managed by her guardian; that is roughly $45 million today. Gloria, who was 10 years old, was called “Poor Little Rich Girl” by most of the papers in the country. The coverage of this trial redefined the standard for sensationalism in journalism and all because her mother was “accused” of being a lesbian. The mere word “lesbian” must have struck such a note with Gloria that she waited until she was 92 and promoting a book to break the news to her son – in front of the press – that she’d had a lesbian relationship. And even with that cloud hanging over her, Gloria openly and lovingly accepted Anderson’s homosexuality when he came out to her.

I love how calmly that Gloria delivers the information and how calmly Anderson takes it. After everything they have been through together, Anderson is probably unfazed by much of what his mother says. Given Gloria’s long and storied life, filled with tragedy, survival and reinvention, I imagine Gloria is not yet done surprising us.

Here is the video:

Photo credit: Getty Images