Dame Joan Collins has spoken out about why she believes it is "tremendously rude" to ask a women her age or discuss it at all.
The 89-year-old Dynasty star, who is more than 30-years older than her husband Percy, still sees herself as a 40-year-old woman.
"I think what is important is not age, but how you look, feel and behave," Collins tells Saga Magazine for the September issue.
On asking women their age, the legendary award-winning film star and mum-of-three adds, "My mother's generation never did it.
"But you know, people have been calling me an older woman since I was 38!"
Her comments have prompted debate on Good Morning Britain, with author Anna May Mangan saying she doesn't think it's 'rude' and is instead proud of her years, and etiquette expert Diana Mather stating you should never ask anyone their age, male or female.
Watch: Dame Joan Collins says it is 'tremendously rude' to ask a woman her age
Despite Collins being up against ageist and sexist attitudes in the industry throughout her career, she speaks more positively of older women being cast in leading roles now.
"I think maybe at last producers and directors have realised that, if they are going to be showing real life in the movies, then they are going to have to have people who are older," she tells Saga, giving Helen Mirren and Judi Dench as examples.
And she herself has no plans to retire anytime soon.
"People say, why don't you put your feet up? I do put my feet up and I don't do anything I don't enjoy," she says. Collins has recently finishing filming the medieval drama series Glow and Darkness with Jane Seymour and the film adaptation of the musical Tomorrow Morning.
She's also written her latest bestseller, My Unapologetic Diaries, painting a picture of her star-studded social life of glitz and glam over the years.
As well as keeping busy and embracing how she feels, rather than how society say's she should feel, Collins eats well and exercises regularly.
But her real secret to looking how she does, she says, is "having great parents who gave me good genes".
It also helps that she doesn't smoke, avoided drugs and excessive alcohol, and moisturises "all the time".
"I never put my face in the sun. I only allow my body and legs to tan," she adds.
Collins recently celebrated her 20th wedding anniversary to fifth husband Percy Gibson, 56, who she dedicated her book to.
"He's the love of my life. It's a great marriage, a great relationship," she says. While she says they have spats here and there, and feels lucky they can have things like separate bathrooms, the age-gap clearly isn't getting in the way.
Collins and Gibson share three homes, in Belgravia in London, LA, and their St Tropez villa, where the accompanying photoshoot for Saga took place.
As well as her latest, Collins is a best-selling author of 17 books in total. Her late sister, Jackie, who died in 2015, wrote 32 books.
Jackie had only told Collins she had stage four cancer weeks before she passed away.
"I was tremendously upset for about three months. I cried every day. The reason I was shocked was that our mother died of breast cancer in 1962 when she was in her fifties."
Collins stresses the importance of having mammograms every year and being checked regularly.
Just months before she lost her sister, she was made a Dame for her charitable services by the Queen, and proceeded to take part in the Platinum Jubilee Pageant this year to mark the monarch's 70-year-reign.
Speaking on her encounters with the 96-year-old royal, she says, "She is a wonderful woman.
"She's inspirational. She's terribly easy to talk to and terribly interested. It's the sort of conversation you could have with your next-door neighbour."
The full interview in Saga Magazine is out on Tuesday 23rd August.