In a chilly night in New York, the fashion designer Marc Jacobs is smoking a cigarette outside the Brooklyn Museum. His hair is dyed jet-black, his buff bod is encased in a bright-green suit, and he wears

diamond earrings of an exceptional number of carats, like Puffy circa 1999. “The earrings cost $50,000, or $100,000, I don’t know,” says Jacobs, waving a hand. Indoors, there’s an enormous party in honour of his collaboration with the Japanese artist Takashi Murakami, with whom he has created a line of handbags. But Jacobs doesn’t want to go in. He prefers to snicker on the steps as celebrity guests file into the galleries.

Jacobs pulls out a camera. “I need some photographs for my MySpace page,” he says. “I don’t know how to post the pictures, so my assistant does it. MySpace makes people happy, which is cool. Also I get very lonely, and MySpace makes me feel better.”

It’s hard to imagine Jacobs feeling lonely, even if there is something about a famous 45-year-old gay guy who loves MySpace. As if on cue, Kristin Davis, the cute brunette from Sex and the City, dashes by. “I love Marc,” she gushes. “He’s just so kind, generous and honest.” Anna Wintour, editor of Vogue and one of his longtime cham-pions, kisses him on the cheek. “Marc has always been a supporter of the arts, so this evening is full circle,” she says, before Kanye West gathers Jacobs in a bear hug, camera in hand. “This guy’s my idol,” says West, handing the camera to his manager to snap them together. “I wish I could hang out with Marc all the time, because he’s so cool. I want to be just like him.”

Jacobs’s collaborator, Murakami, is a pioneer of anime as fine art, and all around the galleries people are dressed like his characters sprung to life. West hightails it past life-size fibreglass models of a lactating woman whose excretions form a skipping rope, and a masturbating boy with semen that has extended to form an improbable lasso. “Man, I want that in my apartment,” West says excitedly. “That way, when people walk in, they know anything is possible.”

In a way, Marc Jacobs is what made this scene possible. It is Jacobs, with bipolar tastes for high fashion (Louis Vuitton) and low celebrity (Lil’ Kim) who helped popularise the current enthusiasm for perversity and art, overt cuteness (teddy bears!) combined with classic cool (Sonic Youth). Like West and Murakami, Jacobs has a pop artist’s hunger to be adored by the right people, and by all the people at the same time — a desire for the kind of fame that is widely in conflict, and tends to foster personal insecurity.

Tonight, this modern sensibility is being celebrated. Jacobs has become the rare designer whose aesthetic transcends the clothes he produces, whose name is known to the masses, is endlessly mythologised in the media and whose reach extends far beyond a label.

“This is what’s happening in fashion in America right now — all the kids look so animated and weird,” Jacobs says, referring to the museum crowd. Pausing, he adds a Warholian thought: “I feel like everyone should have a black outline drawn around them, like a cartoon.”

Earlier this decade, Jacobs came to prominence for essentially mainstreaming the trust-fund chic of Williamsburg, Brooklyn, for making androgynous girls in ballet flats and bespectacled boys in tucked-in shirts sexy, for mainstreaming prissy looks like Chloë Sevigny’s. Now the head of a multi-billion-dollar business that spans nearly all the big fashion markets, with his own label and as the chief des-igner of Louis Vuitton, he is considered the only American fashion designer who matters, with Calvin, Ralph and Donna passé. Sofia Coppola has long been his muse, and other Marco-lettes include Courtney Love and Winona Ryder, who famously shoplifted his clothes from Saks. “I love fallen angels,” he has said. “There are certain girls who make mistakes, and I just love that. I love the strength to move forward. It’s very hard to be someone publicly and then to be human and honest at the same time. It’s a dark angel, not dark like an evil spirit, but a melancholy, broken soul. It’s a good thing.”

In the past couple of years, Jacobs has undergone a shocking physical transformation from a pudgy, Rufus Wainwright-loving nerd to a trim Chelsea boy patterned with over 30 tattoos, in part because of his notions about where the culture is today (a midlife crisis might also have come into play). Surfaces are all that matter and privacy doesn’t exist.

“Young people want to be exposed, and the idea of nobody being interested in your personal life is the worst horror,” he says. “Whether they are Cameron Diaz or not, they want everything they do to feel as important as when you see a celebrity with a cup of Starbucks.” The same could be said for Jacobs. “I’m very interested in Marc and his evolution,” says Stefano Tonchi, style editor at The New York Times. “Going rom that kind of shyness to Marc Jacobs the persona. I think Marc could talk about Marc Jacobs in the third person.”

Jacobs is short and wiry, with a store-bought tan, zero-fat musculature and a nose made broader by artificial means (“I walked into a door once, and I thought it looked really hot,” he says). He’s aware that his new body is a great draw for guys. As the gay pick-up scene has increasingly moved onto the internet, nothing is more important than a photo of your six-pack, and that may have been part of the allure of the gym for Jacobs. He’s dated a series of boy toys, most in their twenties, many of whom have warmed very quickly to the notion of dropping anecdotes about their lover to the gossip columns. Alleged threesomes with porn stars, fights on private jets, the guy he fought with in the lobby of the Beverly Wilshire hotel — it has been well chronicled and extensively blogged about, particularly in the case of Jason Preston, a former rent boy, party promoter and Jacobs’s long-term on-and-off boyfriend.

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