“It was a big surprise that we’d been working on for a long time to set up,” he says of the Paris catwalk turn. “We wanted to figure out a good way to announce that the movie was happening, in a real environment, and not knowing how people would react was really exciting and stressful.”

A sequel, even in an industry when a project can take years to work its way through the various channels, was long overdue. The first Zoolander came out in 2001. Between then and now, Stiller tried once in 2005, and then in 2010, to make another. Finally, in 2013, it was green-lit.

Part of the reluctance of the powers-that-be to fast-track a sequel was because the first one had less than blockbuster box office receipts: globally, it took in a little more than US$60 million, on a $28 million budget. But it burgeoned into a cult hit, with many eminently quotable lines from Derek Zoolander: “Moisture is the essence of wetness, and wetness is the essence of beauty.” People in the fashion, music and pop-culture worlds loved the film, and watched it over and over.

“The constant presence of the movie in social media, in the culture, made it feel like something that the studio would make,” he says. “When we made the first film 15 years ago, nobody knew what it was. It was a challenging experience. I was in a different place. A lot has happened since then, just in life. I have much more of an appreciation for that process this time.

“That time, I felt I had to bang heads. This has been a much better and happier collaboration. It took a long time to work out the budget, the cast, but it all came together, and it finally happened at a time when it felt like there was an audience out there who might want to see it.”

The cameos in the sequel are fast and furious – and were such a hot ticket that the biggest names in fashion and Hollywood were clamouring to be a part of it.

The plot, such that it is, picks up 15 years later; in the original, Ben Stiller’s character is the world’s most famed male supermodel until Owen Wilson’s Hansel assumes his place. Sad and dejected, he is brainwashed by fashion guru Mugatu (Will Ferrell) to assassinate the prime minister of Malaysia, who wants to institute child labour laws preventing Mugatu from producing there.

The plan is foiled, of course, and at the end of that film, Mugatu is carted off to jail, and Zoolander leaves the fashion world to become a philanthropist and father.

For the reunion, which was directed by Stiller and co-written by him, Justin Theroux, Nicholas Stoller and John Hamburg, Mugatu is out of jail, and Zoolander and Hansel are feeling irrelevant in a youth-obsessed world. (Other cast members include Penelope Cruz, Kristen Wiig, Benedict Cumberbatch and Fred Armisen.)

In yet another satirical and implausible story line, the world’s music stars are being murdered while sporting Zoolander’s famous “Blue Steel” look – firm pout, chiselled cheekbones. So he and Hansel are then recruited by Interpol to infiltrate the world of high fashion.

“The beginning of the movie is like wrapping up what’s happened to everybody in the past 15 years,” says Stiller. But what hasn’t changed is Zoolander’s fundamental likeability; yes, Stiller’s character is vain, dim-witted and one-dimensional, but Stiller says that audiences have long been able to relate to his underlying innocence.

“He’s such a specific character, and he has such a specific reaction to everything. He had an innocent way of looking at the world and life and himself. Stepping back into it after a long time was fun and easy. It was very clear how he’d react to every situation. He puts it through a filter of how he sees himself. You can see right through him.”

Both films, while making light work of skewering the fashion industry, are never mean-spirited. Indeed, says Stiller, it’s pretty difficult to be merciless about a business that is known to be brutal. “It’s hard to be cruel to the fashion world – the fashion world is already cruel to itself,” he says. “It’s such a hard world. Show business is hard, too. But fashion – forget it.

“I try never to be personal, although we do make fun of people who take themselves too seriously, which we all do sometimes. And in this Zoolander, the fashion world is in on it. They are willing to make fun of themselves, which makes the movie even funnier.”

Stiller says that he’s conditioned himself to have no expectations, either way: the first film might have been a little slow to take off, but it has an enduring spot in pop culture, and the actor says that he’s fine with the delayed gratification.

“At the end of the day, you just want to feel good about a movie,” he says. “Every time you release a movie, you go through this – the media, the critics, the audience, opening weekend. You get wrapped up in a moment. You want everybody to love it. And then you get through that, and the movie comes out, and that’s when it does or doesn’t have a life.

“That’s why you have to make the choices you feel good about, because that’s where the movie is going to live forever.”

Zoolander 2 opens on February 25