‘I provide the glamour, and she does the magic,” Paul Daniels chuckles when I ask about his show, and Debbie laughs along. Boom boom. The duo’s show Hair Today Gone Tomorrow is on the road again and along with all the amazing magic, tricks and illusions, expect the usual puns and jokes from the Paul Daniels school of comedy.

Because it’s all show business to them or as Debbie puts it: “He’s happiest when performing and making people happy.”

And yet despite their longevity, and the endless reality TV shows, the pair remain an enigma, appearing unscathed by the brutality of shows such as Celebrity Wife Swap, Louis Theroux, The Farm and Strictly Come Dancing.

They admit reality TV is a necessary evil to keep their profiles public, and seem unfazed by the sheer awfulness of their appearances.

Louis Theroux dedicated a skin-crawling episode to the couple, but it’s water off a duck’s back if it means the show goes on.

“We do a couple of high-profile jobs every 18 months,” Paul says, “but that’s showbusiness.” Debbie adds defensively: “But Louis Theroux came out in the days before reality TV, when TV aimed to make you look good rather than trying to get you to look worse and we weren’t used to that.”

Any regrets? “Celebrity Wife Swap,” Paul, 73, grimaces. Anything they wouldn’t do? The Daniels’ recent underwear shoot as Posh and Becks in Closer magazine shows stripping isn’t one of them. And yet Paul ponders the question: “Nothing disgusting or anything Debbie’s mother wouldn’t want to see.”

But that’s why the pair remain so impossible to quantify. They are startlingly honest while maintaining a genuine and private relationship that obviously works and a career that never flails.

“Sure, the Paul Daniels Magic Show stopped in 1994 after 15 years, but everything has shelf life. And Debbie has done her own thing, setting up a dance company, while Paul pottered about at home in Henley.

“We are astonished people are still interested,” Paul says. “But it’s nice people enjoy what we do.”

Another puzzle is how a balding magician married a petite blonde assistant 20 years his junior and managed to make it work. Or as McGee was famously asked on The Mrs Merton Show, “So what first attracted you to the multi-millionaire Paul Daniels?”

Because there is love here. “I am more amazed than most that Debbie is still here, because she is the best thing that’s happened in my life,” Paul says. “Can I have the money now? No, I’m lucky. We wouldn’t do things apart, not over long periods of time. We enjoy jobs working together best.”

That is until Debbie, a former dancer, set up Ballet Imaginaire in 2000, with Paul’s blessing. “Paul loves magic best and I love dance and I thoroughly enjoyed it because people treated me differently.

“Until then they treated me as the bimbo assistant, without knowing my background or education,” she says indignantly. “So for that alone it was worth it.

“But although it was lovely to do, it was a lot of work which took me away from Paul.

“By the third year we were making a profit but it meant giving up everything else and life’s too short,” she says.

So there have been sacrifices to keep the show on the road, but made together. And magic is second nature now.

“I’ve been studying a long time,” Paul says gently, “and I look at stuff and work out how it can be done differently and that keeps me awake at night. I’ve always done 10 live shows a year even when the TV show was on, so when that ended I just carried on.”

What does he think of magic these days? “Magic was never the secret — you have to spend a lot of time on presentation and be an entertainer. And we have the advantage of experience and can generally find a different way to do things. But it’s always been competitive.

“So if I had to define magic I’d say it’s a defiance of all the natural laws that put us on the planet, gravity and solid matter. Magicians have to defy laws of physics and turn them into a theatrical piece.”

The couple could do magic in their sleep, so is it still exciting? “It’s so normal for us, having done it for so long, that it’s like going to the office except we still love it, it’s our life,” Debbie says.

“And the show is much funnier and better than TV,” Paul jumps in. “I found an old wig in a drawer and put it on eBay for £1,100 and my manager thought that was hysterical so we called it Hair Today Gone Tomorrow. The show is funny, not serious. Debbie and I practice it in the kitchen and she tells me what works and what doesn’t.

“People like us together because we are happy people. So we are the ones having the party and the audience comes along for the ride.” I couldn’t have put it better myself.

Paul Daniels and Debbie McGee appear in Hair Today Gone Tomorrow at The Theatre, Chipping Norton, on Saturday. Box office on 01608 642350.