In 2011, after ten years apart, Steps came together to bag a number-one album (a greatest hits featuring only one new song, a cover of ABBA’s Dancing Queen), sell out a lengthy arena tour a year later and trump Lady Gaga in the perfume stakes (Guilty Pleasure was presented in a disco ball-style bottle and outsold the meat-loving diva’s signature scent).

For an explanation of how the manufactured pop juggernaut did it, one has to go to the horse’s mouth.

Ian “H” Watkins bats away the idea that a lack of alternatives opened up the road for the whirlwind comeback, which finally wrapped up with a Christmas album, Light Up The World, and more seasonal touring at the end of 2012.

“Nostalgia crept in,” he says, speaking from the changing rooms of a theatre in Glasgow, where he will later perform as the lead in the latest touring production of Andrew Lloyd Webber and Tim Rice’s West End classic, Joseph And The Amazing Technicolor Dreamcoat.

“Back when we were around first time, there were Steps fans who didn’t want to admit it but we became kitsch and cool.”

The Steps tour was booked on the back of a reality documentary made for Sky Living to promote the greatest hits album, The Ultimate Collection. H says the shows were never planned but calling the series Steps: On The Road Again suggests otherwise. “The reunion was never meant to be a reunion. It was just supposed to support a documentary to support the greatest hits. Then it turned into this monster that nobody could stop. It is something we are talking about carrying on in the future, but not this year.”

When revelations such as H choosing to fly in Britney Spears’ private jet rather than travel with the rest of the band broke in the first episode, up went the viewing figures and fans’ hunger for a full-scale reunion.

“It was a bit like therapy,” says H of filming the fly-on-the-wall TV show. “Part of it was enjoyable, part of it wasn’t. Once we’d waded through all the mud and all the issues then it became enjoyable.”

He loves a bit of reality TV. H Side Story followed him retraining at the Royal Academy Of Music when the short-lived duo H & Claire (with former Steps bandmate Claire Richards) went the way of Steps. He also came fourth on Celebrity Big Brother in 2007, in the series with Jade Goody and Shilpa Shetty at each other’s throats.

With all this microscopic exposure, does he ever feel like he gives too much of himself away? “Erm,” he chirps. “It all depends on who the show is aimed at and if you are in control. With something like Big Brother, you are completely not in control.

“That was surreal, totally and utterly. We were kept from everything that was going on in the outside world. I didn’t realise the extent of Jade and Shilpa’s row until I came out. Luckily, I wasn’t part of any of those conversations. They all happened behind my back, so I was completely unaware.”

H came out in public in The Sun before he entered the house.

“I was nervous. But I was just confirming something everybody knew really. It wasn’t exactly a major secret.”

Why does he do reality TV?

“You have to get something out of the experience personally. On H Side Story, I learnt a lot about myself. I wanted to show that you can’t rely on what you’ve done to get you through. You have to work hard and apply that to your job.”

With H-Side Story he rediscovered his love of theatre.

“The reason I went back to college was to make myself more aware of the tools I had as an actor and to improve my technique as a singer.”

H first got on stage in an am-dram production of Joseph when he was nine. “I played the youngest brother Benjamin. I used to watch Joseph in the wings and wish that was me.”

He was soon performing in the West End – aged only 11.

“Theatre is where I started out. I did a lot of work around Wales throughout my teens and then I just fell into Steps. Theatre is where my heart lies and always will.

“I wouldn’t say I enjoy it more than music. I am just very fortunate that I get to do lots of different things with my job. I love theatre but I also enjoy being a pop tart as well.”