the monday interview Calvin Klein; The Ice King of Madison Avenue

"He is here!" says Calvin Klein's make-up artist. She is peering out of the third-floor display window overlooking Madison Avenue. Hesteps out of the limousine, looks up at his brand new store, then down at the pavement again to steady himself. "Don't mention the sun," warns the make- up artist. "He is very sensitive about his skin." His hair is another sore point: "He has just had that crew cut done ... best not to talk about it."

Klein disappears into the building. We wait. Security guards are talking into discreet microphones. Sales staff look flushed with anticipation. "Are you nervous? Are you nervous?" the make-up woman asks. "If you are - don't worry. He is so charming he'll put you at ease ... he has tremendous charisma."

The man enters. Calvin Klein. Aged 52. Acne-mottled face (despite collagen shots). Short hair. A membrane-like bald patch. We shake hands, then he sits in one of his excruciatingly impractical chairs - crouched like a frog, knees up round his ears. Does he mind if I sit on the table? He is too cool to say no, even though he worries about the whole thing tipping sideways. Instead he just coughs - long, hacking. I wait for him to stop, wondering when the spluttering will finish and the charm will begin. It doesn't happen. He just sits there and waits.

For more than a quarter of a century this man has been heralded as one of the most talented trendsetters in the world. His name is synonymous with underpants, he gave us "androgynous" perfume, he managed to eroticise jeans using pre-pubescent teenagers. This also happens to be the man who designed my first ever "work" suit (faux-fur collared jacket and pencil skirt in gorgeous wool and cashmere). So how did he get it right? Who is this person who seems to understand women's bodies, needs and desires?

Who buys Calvin Klein clothes? "Modern women," he says. "Women who work, have families, who are busy. Women who like clothes and enjoy feeling feminine. Not ladies who sit and lunch at four-star restaurants."

What about age? "Age doesn't matter," he says, "as long as people want to do things, have ambition, have energy."

Klein courts wealthy, "professionally established" female customers by creating well-tailored, classic designs in natural fibres. His clothes meet the needs of working women who want to feel authoritative as well as sexy and feminine. Klein gives them what he wants, but he doesn't sell his name on the basis of these products. Instead he sells the Calvin Klein image using Kate Moss's unattainably youthful, breastless, hipless body.

Why pick a female model with a man's figure? "We sell a lot of small sizes," is Klein's explanation. What about his typical customer's body? "Chances are she exercises to keep herself in pretty good shape," he says. "I don't go above size 14 ... It is not that size 14 is bad," he adds hastily, "it just means strong bones, strong shoulders ..."

You would have thought Calvin Klein would know how to play women: he says his second wife, Kelly, determines the direction of his business; his mother, Flo, is a persistent source of inspiration; his daughter, Marci, keeps him up to date with the fashion world. "I am surrounded by women who are determined and passionate about the things that we make," he says with a tone of resignation. "They practically run our company."

He keeps the tone of the conversation strictly professional: eye contact is unwavering and cold, answers are perfunctory.

Klein was born in the Bronx on 19 November 1942. His father, Leo, was a Hungarian Jew who scraped a living as a grocer. His mother organised the household and brought up three children.

By the age of five, Klein knew what he wanted to do. He started by making clothes for his sister's dolls. Later, he tried his hand at making dresses for Flo. Children in the Bronx had a word they used to describe boys interested in girlie clothing: faygeleh. It's Yiddish for "little bird" or "fairy".

At 18, Klein enrolled at the Fashion Institute of Technology, where he developed a snobbish contempt for anything synthetic or colourful. After college, he freelanced. Then in 1968, aged 25, he decided to go it alone. With the help of Barry Schwartz, a childhood friend (and now business partner), he started his own label. The first sample collection was spotted by a buyer from Bonwits, the now-defunct Fifth Avenue department store, and an order was placed for $50,000.

By then, Klein had married (in 1964) and become a father (Marci, born 1966). He had also started dallying with men, according to reporters Steven Gaines and Sharon Churcher, author of Obsession, an unauthorised biography of Klein. One male lover remembers Klein's sexual technique as being "hardly inexperienced". Klein is said to have learnt about sex in Europe. "He didn't dare do it in the United States for fear that someone would find out," said a former lover. By 1974, Klein's marriage was over.

Some say that Klein left his wife for another woman, Lizette Kattan. Others say Klein was "infatuated" with a long series of houseboys who tended the apartment. "He was like a kid let loose in a candy store," claim Gaines and Churcher.

Andy Warhol writes in his Diaries about how he visited Calvin Klein on Fire Island and found "8,000 boys" hanging around Klein's house. Warhol remembers that he was afraid to be kissed by Klein because "his beard was stubbly" and he was afraid that a stubble might pierce "into my pimple and be like a needle and give me Aids".

After 10 years of being the playboy, Klein decided that he'd had enough of living out his fantasies through drinking, drugs and sex. He started seeing Kelly Rector, 23, the company design assistant, coy, colt-like and cute. "But Calvin likes boys," Giorgio Sant'Angelo is reported to have said, disgruntled. Nevertheless the friendship developed, and in 1986 the two married.

The speculation hasn't stopped. Gossip was fuelled again by the recent furore over a homoerotic television campaign featuring a male youth being propositioned by an (unseen) older man. "How old are you?" the rasping voice intones. "Are you strong? You think you could rip that shirt off you? That's a nice body. You work out? I can tell."

"We didn't intend it to be pornographic," says Klein. "The purple carpet was supposed to be a spoof - to poke fun and satirise traditionally suburban settings such as shopping malls and people's homes ... but I can see that people could get the wrong impression." His 25-year-old daughter thought the uproar was "nonsense". As did Kelly. "We wanted the setting to be tacky and sexy ... it's fun ... we just wanted to give people something to think about."

He starts talking about his family. How everything is test-driven on his wife and daughter. How he "always wants to know how she feels". About what? About their business. So - are you - still married? I venture. "Yes," he says, stopping a moment and eyeing me flatly. "And yes - we are still living together."

I feel cruel. Klein's sexual preferences are his own business. But then he will insist on promoting this clean, oh-so-modern caring and sharing image: weekends in the country with his wife; plenty of outdoor life; perfumes embodying heterosexual "oneness" and "eternal marriage". Household items to re-create nesty, lovey-dovey retreats. Is this preoccupation with "purity and cleanliness" a reflection of the new "rehabilitated" Calvin Klein - the drug-free, heterosexual, family-oriented Calvin Klein?

"Rehabilitated?" he repeats weakly, adopting that Reaganesque habit of cupping a hand round an ear and pretending to be deaf. Well - how about reborn? There is a silence. Then he replies (tightly - so as to make it quite clear that he will not be drawn into a discussion about his past): "No, it is the original."

On to the big question: What do women want? What dark needs and passions has he unearthed in his quest for the ultimate, tailored, Klein-esque suit?

He thinks for a moment. "She wants to feel good, look good," he starts. "She wants to feel like a woman without being treated like a fashion trophy. She wants clothes that are comfortable, clothes that make her feel younger. Sensuality is important, too: fabrics that feel good, looks that are sexy. A masculine jacket, for example, with something feminine under it - a silk slip perhaps."

From whom did he learn this? "My mother," he says proudly. "She likes clothes that are extravagant in an understated way. Sophisticated. White. Not something which screams from the other side of the street."

The interview finishes. In sweeps the Klein army - one to rush me out, another to clean up the room, another to escort him to the make-up artist who has been waiting for an hour-and-a-half to rub some tinted moisturiser into his face to "cover a few things up". At 4.40pm, he emerges for the photo shoot. "I've got a meeting at 5pm," he tells our photographer, who has been promised an hour. "So what?" says the photographer. "I've been here for nearly two hours." Klein looks askance. Then: "Well, let's get on with it."

I watch Klein from a distance, noting how he manufactures an aura of authority and charisma. He does it by ignoring people who are standing waiting to be introduced until it verges on the rude. Or by effusing gallantry and politeness to his customers while baring his teeth at the staff. He licks his lips and preens for the shots he approves of (standing king- like over Madison Avenue), then becomes jumpy and grumpy in the poses he dislikes (a portrait taken in the cramped stairwell overlooking the shop).

As he prepares to leave, we all line up to say our goodbyes. He makes us feel that we are shaking hands with royalty. He gives me the CK take: hard eyes, terse smile, before offering his hand indifferently to the person beside me. Then he turns and - chonk, chonk, chonk - runs down the stairs. The Klein army exhale a collective smile of relief. The photographers burst out laughing.