God forgive me - I interviewed Christian Louboutin while wearing a pair of trainers. Not fancy sci-fi ones either but properly old and grimy ones. Louboutin is one of the most famous shoe designers in the world and officially the most prestigious, according to independent ratings company Luxury Institute, which named Christian Louboutin as the most desirable shoe brand in the world for the past three years. He is also the man who is credited, or blamed, for bringing the stiletto back into fashion. So wearing trainers to meet him is a little like suggesting to a Michelin-starred chef that we meet at McDonald's for lunch.
But then - whaddyaknow - Louboutin turns up to his tiny and stiletto-filled office wearing trainers himself. (Although where mine say Converse, his say, in a discreet logo on the side, Christian Louboutin, which would come in handy should he forget his name.)
"Your trainers are nicer than mine," I say as we settle on the striped sofa against the wall.
"Oh, non ... " he drawls in a tone that says, "Oui, oui, oui, oui, oui".
But he assures me that he does not judge women by their shoes. Well, not exactly. "I look at the face first. And when I look at the face, I try to see the personality and, from that, guess what kind of shoes this girl would have."
"So what shoe would my face suggest?" I ask. He stares at me very intently for five seconds before answering: "A Dr Marten boot."
Perhaps he was just tired. He had flown in that morning from Dubai, where he is about to open his 20th boutique - with 13 more planned this year - and did not sleep on the plane "at all". And once he warms up and we turn the conversation away from strict business chat, he is really good fun, making dry remarks and then smiling quietly afterwards. At one point I ask if, having shod pretty much every celebrity in the world, from Madonna to France's first lady, Carla Bruni, there is anyone left he'd like as a customer. His eyes skirt around the office, settling at last on a pair of particularly high black stilettos, studded all around with silver spikes. He turns back and replies, po-faced: "The Queen of England."
For a long time, perfume sales powered the fashion world. Then it became jeans. Now, more than ever, it's shoes and bags. It is no coincidence that Louboutin arrived in the '90s, when this switch began. He, Manolo Blahnik and Jimmy Choo's Tamara Mellon, the Holy Trinity of the luxury footwear market, have helped turn shoes from something you put on your feet to avoid splinters into fetish objects for women. Louboutin is now at the top of that triangle.
Where Manolo Blahnik shoes are either plain or quirky and Jimmy Choos have the distinct sheen of Eurotrash to them, Christian Louboutin shoes say one simple word: sex. Everything about them - from their disco styles to the aggressive thrust of the shoe's curvature and to the almost-pornographic red sole, flashing observers from behind as the lady walks away - shouts sex.
Seemingly every celebrity under the paparazzi sun, from Lady Gaga to Victoria Beckham, has proclaimed their love of the man. But Louboutin himself proves to have remarkably little interest in the international celebrity scene. Was he star-struck when, say, Madonna was photographed wearing his shoes? No, he wasn't. But he was a little excited when he found out that the first Mrs Johnny Hallyday was a fan - "Hallyday is a big singer in France, you know."
Louboutin also recently received the highest honour a shoe designer can receive these days: his wares are to be featured in the new Sex and the City film. This is not only a major plug but a potentially controversial one, as Manolo Blahnik shoes were such a mainstay of the TV series that the term "Manolos" entered the lexicon. But is Louboutin excited?
"I think it's a good thing because people tell me it is. I don't have a TV, you see," he says with a shrug.
There is a heel that is too high to walk in, certainly. But who cares? You don't have to walk in high heels.
Any awkwardness between him and Blahnik? Another baffled shrug.
He even refused to go on The Oprah Winfrey Show when she did an episode about how much she loves his shoes, which is as close as you can get to being knighted in the US. "They filmed the first part of the show in Paris and made me stand outside in the cold - so, of course, I got sick," he says, still outraged. "So then when they said, 'Come to Chicago' [where Winfrey films her show], I said, 'Are you crazy? I'm sick!"'
Instead, Louboutin prefers his hobbies: landscaping (there are often plant details on his shoes), trapeze (he has a swing in his studio) and, occasionally, dancing. He recently made a film of himself tap dancing for Simon Fuller's fashion website, Fashionair, which is a vision of unselfconscious joy (and, yes, he made the shoes).
Is he a regular tap dancer? "Well," he says with a hint of understatement, "I've got rhythm."
Most of all, he works: supervising the factories, having meetings around the world and then, twice a year, he will isolate himself in one of his four country houses (Egypt, Syria, France, Portugal) while he designs the new collections.
"I never was interested in being part of the fashion world - I just wanted to design shoes. I didn't even know Vogue existed when I was growing up. Vogue, what is that?" he protests.
A few years ago, Louboutin was offered the job of designer at a major fashion label, though he won't say which one. "And I really was almost offended," he says, still sounding it. "I mean, the shoe - there is a music to it, there is attitude, there's sound, it's a movement. Clothes - it's a different story. There are a million things I'd rather do before designing clothes: directing, landscaping. Designing clothes?" His face indicates his opinion of that.
Louboutin was born in 1963 and raised in Paris. His father was a carpenter and his mother was "definitely not" a high-heel fan. His four sisters liked "cork wedges", he remembers, with no fondness. "Pretty much the opposite of what I do now."
Yet his taste was established in his childhood. When Louboutin was 13, he and his friends would sneak out of school to go to Le Palace, a Paris nightclub, but while his mates looked at the girls on stage, he just looked at their shoes. "Some of the shoes I make today are still inspired by the Palace - the disco look, the metal, the glitter."
He never went to fashion or design school and instead got his training working for, among others, Charles Jourdan, Chanel and Yves Saint Laurent.
He is adamant that he never had any career plan or ambition to own his own company, which I don't wholly buy. It is very hard to be successful without wanting it very badly, particularly in the fashion business, and Louboutin, for all his Gallic nonchalance, does play the game. He once decided to miss a flight back to Paris from the US so he could spend two more hours in a department store autographing his shoes. "To my favourite hot housewife," Time magazine claimed he scrawled on one customer's shoe.
Today, Louboutin shoes are known for two things: price and height. A pair of Louboutin high heels can easily cost upwards of $1100; boots can go for $2000 and higher.
As well as being in the vanguard of higher prices, Louboutin is at the forefront of higher heels, bringing stilettos back into fashion, together with all the contradictions that come with them. Jennifer Lopez once told Harper's Bazaar magazine that Louboutin's shoes "kill you. But they're the sexiest shoes around." How can immobility be sexy?
At this point, Louboutin starts talking about "the construction of the shoe" and "the direction of the weight" and all the usual noises people make when trying to claim that a high-heeled shoe can be comfortable. But the fact is, no matter what the construction, the woman is hoicked up on her toes. The argument about whether or not high heels empower women is fruitless and, after all this time, a little tired.
But even Louboutin seems stumped by the contradiction. When I ask if comfort is an important factor in designing his shoes, he ums and ahs a tad: "It is important because a woman doesn't look good if she's not comfortable. But I wouldn't take it as a compliment if someone looked at one of my shoes and said: 'Oh, that looks like a comfortable shoe.'
When asked if there is such a thing as a too-high heel, he replies: "There is a heel that is too high to walk in, certainly. But who cares? You don't have to walk in high heels."
Germaine Greer recently wrote, citing Louboutin in particular: "While feminists have been struggling to set women free, high heels have conquered the world."
"I haven't heard that kind of idea since the '70s. Thank God that childish idea has vanished. Who said that?" he asks sharply.
Germaine Greer. "Who's that?"
A feminist academic. She wrote a very famous book in 1970 ... "There you go, she's a '70s feminist. She's keeping her bases covered," he interrupts, settling the matter. For the defence, Louboutin cites one of his customers, Madonna - "And she's pretty independent."
Last year, Louboutin signed a deal to make a special Louboutin Barbie. He agreed on one condition: they would have to slim down the doll's insufferably fat ankles.
"Did you really tell them to make Barbie's legs thinner?" I ask, expecting him to deny it.
"Yes," he replies without a blink. "The ankle was a bit straight and there's nothing more pretty than a very curved ankle. So I said to them, the one thing that could really give her perfection is to give a curve to her ankle." He smiles. "It's not like she's going to suffer for it."