Sting's daughter Eliot Sumner has said she did not come out to her friends and family because they "always knew".
Speaking about her sexuality for the first time to ES magazine, Sumner revealed her two-year relationship with Austrian model Lucie Von Alten.
"No one had ever asked," she said when questioned about coming out.
"They knew already," she added. "So I didn't need to. I've never come out to anyone. My friends always knew and I always knew".
The 25-year-old, also known as Coco, is the third of Sting and Trudie Styler's four children.
Sumner attended a private school in Dorset before moving to London to study at the Fine Arts College in Belsize Park.
She has followed in her famous father's footsteps and is a singer-songwriter.
First album The Constant, released under the band name of I Blame Coco, debuted in 2010.
Information, the second album, is due out next month.
A couple of songs on the upcoming release are about Sumner's girlfriend. The couple live together in London's Belgravia.
The Italian-born singer defines herself as a "musician" and does not identify with a particular gender.
"I don't believe in any specifications," she told ES magazine.
"I think forever I was trying to figure out maybe ... what I am. But I don't think anyone should feel pressured to have any kind of label or tag on them.
She added: "We're all human beings."
Her voice has been compared to her father's, most notably on 2011 single Self Machine.
"Sounds at times uncannily like Sting," a reviewer for The Independent wrote.
It is something, she says, that has developed over time.
"I can't really control what I sound like," Sumner stated.
However, she is aware of the challenges children of established stars face.
"I think I'll always be in the shadow of my parents," she said.
"But that's OK. Everyone has a challenge. If I'm proud of the music I am making, that's all I can ask for. If I put it out into the world, it's not up to me any more."
Information will be released in January, 2016 on Island Records.