Percy is my accomplice, best friend plus he's extremely handsome

Age is a dirty word in the Collins household. Not because Dame Joan is scared of her 90 years. Nor because her beloved fifth husband happens to be a few decades her junior.

- JESSICA BOULTON

But because she has always believed the secret to ageing well is to... well, refuse to even give it the time of day.

"Oh! We don't mention that," she laughs, when asked about that birthday milestone in May. "I'm 60... plus however many years."

It explains why she still has a work and social diary to rival Alexis Colby in her Dynasty prime.

There is the new book - her 19th - Behind The Shoulder Pads, an upcoming UK tour of her new one-woman show, a food partnership with Marks & Spencer, a passion project about Wallis Simpson (which may or may not go down that well with her royal friends), and a whole host of shopping to do before guests arrive for that night's regular poker game.

It is quite the full dance card for a screen icon who could once count Jimmy Dean, Gene Kelly and Marlon Brando as pals. Not to mention, one who has known Liza Minnelli since she was a babe in Judy Garland's arms.

"There's far too much fuss about ageing, she says. "You see people in their 90s and 100s doing amazing things - running and jumping on Instagram - there's no reason to fall apart. I do my stretching exercises each morning and I have a trainer on Zoom three times a week.

Her routine, she adds, includes "standing on one leg for almost a minute", an idea which would defeat many half her age.

However, one might suggest the real reason for her joie de vivre has less to do with her balancing skills and more to do with the happiness and stability she shares with hubby number five, Percy Gibson, 58.

The pair celebrated their 20th anniversary last year: a bona fide slap in the face to former sceptics of their 32-year age gap, and perhaps one reason why she is ready to open up about their relationship in a way she never has before.