A 71-year-old ballroom dancer said she had no idea she had been cast in a Taylor Swift music video until ten minutes before filming.

Denise Sides, from Wrexham, was selected by the global megastar to appear in Opalite - a 90s-inspired rom-com that brought together the cast of an episode of the Graham Norton show.

The dance teacher said she auditioned for an "unknown artist" and once cast, the top-secret job involved being sent to the filming location in discreet transport.

"Then this young girl walks in, all dressed up, and she comes over and says, 'Hi, I'm Taylor," said Sides. "I was like, no way. Oh my God."

Sides, who has been dancing for 60 years and teaches ballroom classes, said she had signed up for TV extra work through an agency and responded to a call-out for senior dancers on behalf of an "unknown artist".

After being shortlisted, Sides received a call confirming she had been specifically chosen by the artist out of hundreds of applications.

But she had no idea record-breaking Swift was behind the request.

Sides said the whole experience was "hush-hush" and all she had been told was that the job involved recreating a dance competition.

It was only ten minutes before filming began that she found out the video was for a track from Swift's latest album, The Life of a Showgirl.

Sides, a Swiftie herself, said she was in shock when the singer walked in.

"I still feel excited now [remembering it]," she said.

Sides said Swift, who sang in and directed the video, put everyone at ease during filming and thanked dancers for their time.

"She knew exactly what she wanted. She'd say, 'try this, try that,' and she was really nice about it," said the dance teacher.

"Some can be a bit abrupt, but she wasn't. She was lovely and so talented."

In the video, Sides is seen wearing a royal-blue ballroom-dancing outfit she has owned since becoming a professional dancer in 1988.

She said Swift complimented her outfit and said, "I love your dress. It really fits the set."

When Sides saw the video, which was filmed in November but released earlier this month, she said she was gobsmacked.

"You just can't believe it's you," she said.

It was difficult to keep the experience a secret too, she added: "It was hard, I only told a few people in my dance class and my family."

Opalite features Domhnall Gleeson, Lewis Capaldi, Greta Lee, and a cameo voiceover from Cillian Murphy, all of whom appeared on the Graham Norton show with Swift in October.

It tells the story of a lonely woman who uses a magical spray to improve her life and finds romance with a fellow loner.

Despite dancing her whole life and with decades of acting experience, Sides said the shoot with Swift was the most important of her career.

She said she hoped her experience would inspire others to try dancing.

"Maybe people will think, 'Well, if Taylor chose her, why don't we?'," she said.

"You're never too old. It was an experience I will never, ever forget."

In addition to running Dens Dance Studio since the 1990s, Sides also hosts inclusive workshops for those with disabilities.

"If I'm not teaching, I'm dancing myself," she said. "That's my happy place, my passion."