The Jean Paul Gaultier circus hits town

Jean Paul Gaultier and I are locked out on the pavement. It is chilly and many superstar designers would be impatient, conscious of time ticking past as every second another Madonna-style pointy bra or corset dress hits the high street, blithely ripping off Jean Paul Gaultier's original design, and every day another celebrity wants him to dress her (Beth Ditto, Crystal Renn, Lady Gaga). But JPG is not remotely bothered by our enforced hiatus on the Mayfair street, erupting instead into giggles, then beaming patiently. Like a naughty, fashion-tastic Dalai Lama, he is wonderfully playful, benign company, even though, 20 years after he designed Madonna's

He has just put down the reins at Hermès with a knockout final Paris Fashion Week show featuring leather corsets, gaucho hats, Erin O'Connor and eight prancing stallions. Now, at 58, perhaps JPG will focus on his haute couture line, go island-hopping with his Greek boyfriend, maybe release another few variants on his iconic perfume, continue with his La Perla underwear line but generally take it easy. Pas exactement.

He tells me passionately that he would like to splatter the Pope in red paint. 'Haemoglobin, all over the Popemobile, that is my suggestion! That is how I dress the Pope.'His accent and speech patterns are truly, deeply, parodically French; if he were an actor in 'Allo, 'Allo!, you'd think he was laying it on too thick. It takes three goes at 'aaaa eeeel'before I realise he's saying 'high heel'. He is too late for Il Papa's visit to London, but he applauds those who did demonstrate: 'At that, the Anglo-Saxons are very good.'His Catholic faith, never particularly strong ('Sorry, God, I am sleepy, I will do my prayers tomorrow'was his stock formula as a boy, he tells me), is waning because of the Pope's continued stance against condoms, regardless of the HIV epidemic. 'His word is deadlier than the sword. This is scandalous criminal. I should become Protestant! You can have sex only for procreation?'He pops his pale blue eyes. 'They should accept reality!'

He is about to do something constructive by lending his talents to The Elton John AIDS Foundation, becoming 'creative director'of its fourth Winter Ball, the Grey Goose Character & Cocktails party. It looks to be an opulent, surreal affair. 'You know I love trompe l'oeil, so I started with my sailor stripe'– he gives a little smile at the thought of the butch Breton stripe that is his high-camp trademark – 'and I put it on the wall and after it becomes the carpet and after it becomes the furniture'With people dressed in stripes dis-appearing into the wall? 'Maybe! I love it when you don't know where the beginning is, where the ending is, or whether you are flying'He assures me there will be a safety net – 'like a huge fishnet!'– though to say what for, or for whose safety, would spoil the surprise. 'And one room will be full of crystals, like the movie Tron [the 1982 Disney sci-fi drama starring Jeff Bridges], where all the perspectives are changed. I am the only one to do my own restrictions here.'Sir Elton is equally excited at the prospect of what his old friend has in mind for the ball. 'I just can't wait to see what Jean Paul is doing with the space,'he says. 'The invitation alone is fabulous.'

Gaultier goes on: 'It is so exciting. I do [charitable] things, but maybe not enough. Now I finish at Hermès, maybe I will have some time to do some more. Truly I saw so many things that I want to help. Always with illness there is injustice, but especially with AIDS. There is injustice because out of love comes death. There is also injustice in the way people stigmatised AIDS [sufferers]. People refused to touch them, even professionals in hospitals sometimes. Someone I knew, his parents truly did not want to see him any more, it was horrible. He died surrounded by people from the hospital and his friends. I have seen it with people around me, my friends, and especially'– his voice is very low now – 'my boyfriend.'

Francis Menuge, his lover and business partner, died of an AIDS-related illness in 1990. They met in 1975, when JPG was 23 and had just returned to Paris from a stint at the Pierre Cardin workshop in Manila (he never went to college). They were introduced by JPG's sole friend from school: 'My only one friend, he was gay also; we did not have an affair but maybe our sensibility was the same.'One look at Menuge and JPG was smitten. 'He was beautiful, very good-looking, tall, handsome, French with a little Italian blood. But most of all he was lovely, brilliant, clever and creative. I think I fell in love when I saw him and then I realised he was creative, you know. We were speaking the first day we met, he was saying, "It would be nice to have a small cascade of water down this wall." It's a small example, but oh my God it's a good idea.'

Menuge was 'super-good in electronics'and helped start Gaultier's first independent project, a line of kinetic jewellery that lit up when the wearer moved. 'He believed in my, let's say, talent to make clothes and gave me the confidence to go further than I should have done, because I was not ambitious. He was ambitious.'I can believe it – ambitious people tend to find being locked out on pavements frustrating. 'Of course, it was the work I should have been doing anyway. Since I was 14, 15 years old, this is what I wanted to do and before that I was dressing my teddy bear in a cone bra. But he gave me the confidence, the love; that's what it was. He was my perfect partner.'

Behind every megastar creative is a steady business brain, and Menuge nearly became a lawyer or 'it's horrible to say it but a politician'. He was the perfect counterbalance for Gaultier, who had long been an outsider. An only child who grew up in the left-wing commune of Arcueil, just south of Paris, Gaultier's one moment of glory at school was when he was punished, aged eight, for his sexy drawing of the dancers of the Folies Bergère, all feathers and fishnets. He mimes the teacher hitting him – 'Dung, dung, dung!'– on the finger with a ruler. 'Rulers were hard then.'Next she made him take a tour of the classrooms with his sketch displayed on his back. 'The guys laughed and smiled. It wasn't negative. It was, on the contrary, acceptance – like a passport.'

His father was an accountant and his mother the cashier at a local government canteen, and he spent lots of time with his grandmother, a spiritualist healer whose sessions he quietly observed. 'She was a nurse but she was also doing magnetism, massage, tarot readings, beauty masks with her clients, giving them advice about how to keep their husband Maybe that helped me understand that the spirit and psychology are connected with the way you look, what you can say about yourself if you change your hair.'His grandmother, needless to say, read a dazzling future for him in the tarot.

After watching a film by Jacques Becker called Falbalas, about a couturier, JPG knew what he wanted to do in life. Cinema is deeply important to him. His pinstriped suits for women were inspired by the 1959 television series The Untouchables: 'These costumes made an impression on me, they are part of my vocabulary.'The Le Male Breton sailor stripe, on the other hand, refers back to the way his grandmother used to dress him as a child. He went on to design the costumes for Luc Besson's The Fifth Element, Pedro Almodovar's Bad Education and Peter Greenaway's The Cook, The Thief, His Wife and Her Lover. His favourite films, he tells me, are Terry Gilliam's Brazil, Blade Runner, The Adventures of Baron Munchausen and Avatar. 'The dreamy, surrealistic movie, that's what I prefer. Oh, and Muriel's Wedding.'

With Menuge, he built up a huge global business, working with the Japanese designer Kashiyama and launching Junior Gaultier for children. Then the illness struck. 'He was sick for, let's say, one year. His immune system was not working, which meant there was water coming all the time from his stomach. Three months after he died, there was something to cure this. There is urgency with this fundraising.'JPG is also on the board of the Carla Bruni-Sarkozy Foundation. He has known the French First Lady since her modelling days. 'Her brother died of AIDS. It's a sad motivation, but when you realise people you love are disappearing you have to do something.'

When Menuge died, JPG considered 'for a short moment'the idea of shutting up shop. 'Already I went higher than I should expect, so maybe I should stop, but no, it's like a baby we had together, I should go on.'And so he expanded into touring costumes, set design, furniture, fragrances, vodka advertisements, haute couture and, in 1998, Jean Paul Gaultier Fourrure, a fur dif-fusion line. This has led to an ongoing feud with PETA (People for the Ethical Treatment of Animals).