He has all his clothes on today, which is almost a surprise given Juergen Teller's willingness to strip off for his art. He looks respectable in his well-cut suit, plain T-shirt and leather boots. His blue eyes are piercing but his salt-and-pepper beard makes him look more like somebody's uncle than an in-your-face photographer. Albeit an uncle trying quite hard to be trendy (the spiky hair).

In the architecturally reconfigured west London Georgian terrace that’s his home and office, Uncle Juergen makes me a lovely cup of tea and politely asks me about myself. But I’ve seen him crouched naked in the snow, dangly bits curiously unshrivelled by the cold. I’ve seen him urinating naked onto a pot plant. I’ve seen him sprawled naked on a bed, casually full frontal. And I’ve seen him drinking beer – stark bollock naked, again – on his father’s grave.

Those are just a few of the photographs he has taken over the last few years. Nobody could call any of these images forgettable. Nor, having viewed it once, is it easy to purge your mind of Teller (naked, obviously) contorted into an odd position, bum towards the camera, balanced on top of a grand piano that’s being played by a fully dressed, elegant-as-ever Charlotte Rampling.

Yes, that’s right, the fabulous ice-hot Charlotte Rampling. She’s a friend of his, you see. When they first met, eight years ago, on a shoot, she was a bit stern until he showed her one of his books. Then, ever the experimenter, she got interested and they were off. They collaborated rather intimately on this project, Louis XV. With the help of Teller’s wife, the art dealer Sadie Coles, he and Rampling went on “a fantastic adventure”. What a wonderfully barking set of pictures. “I think they’re humorous and tragic,” he says. Thank God we’re allowed to laugh. At the same time, he takes it very seriously. “This hadn’t been done before,” he says; and it’s true, you don’t often see an over-60 woman being naughty with an overweight fortysomething man. Here’s Teller with his tongue in Rampling’s ear. There’s Rampling’s face next to his caviar-smothered groin. In this one, he’s sucking her toe. In that one, oh dear, he’s on his own, looking slightly disconsolate. But wearing her lipstick. And there they are curled up in postcoital bliss – or perhaps in the disconcerting embrace of a mother and son who are too close. He likes this ambiguity. When he describes making this work – which took six months, on and off – he gets slightly schoolboyishly breathless, as if he can’t believe his luck. “As she’s doing it, I’m thinking, ‘Oh my God!’ ” he exclaims. “I remember when I first said, ‘Charlotte, I’ll need to kiss you and fondle your breasts.’ She sat back and had a cigarillo. Then she said, ‘Okay, let’s start.’ It was so exciting! It was what I wanted.” A lot of men would want that, I say. “Yes, but they didn’t ask! I asked!

If you don’t ask, you don’t get.” He chuckles

in satisfaction. The setting was the opulent £6,300-a-night Louis XV suite in Paris’s Hôtel de Crillon. We’re talking many a thinking man’s fantasy here. Decadence, luxury and one lucky bloke with a beard (who uncomfortably reminds me of that man on the original Joy of Sex book cover). Imagination features highly in his work. Yet Teller made his name by striking through the shiny, fake-smiling aesthetic of the 1980s and replacing it with something more real.

He came to London from a Bavarian village in 1986, full of Catholic guilt and a desire to break free. His father was an abusive alcoholic. His mother remains a great strength and support. Teller worked in the family business, making bows for string instruments for a year, until he had an asthma attack. He hated school and had no desire to do national service. “I never understood authority,” he says. “I had to do what I wanted.” So, with the optimism of youth, he moved to London to become a photographer.

The first nine months were hell, he says, as he struggled to learn English and find his feet. Then he started photographing album covers and going on tour with grubby, angst-ridden bands like Nirvana, which led to his being invited to do similarly non-glossy fashion shoots for the era’s edgiest magazines. Soon he was photographing Kate Moss. He still does lucrative fashion campaigns to subsidise his arty projects. But he has also made subversive, provocative work about the industry. One project, Go-Sees, consists of photos of hopeful young wannabe models on his doorstep, images full of pathos and desperation. In his latest Marc Jacobs campaign, he has Victoria Beckham inside a carrier bag, legs splayed out, as if she’s a product. She was in on the joke. “We’re laughing with her, not at her.”

He says he never wants his subjects to feel uncomfortable. Women trust him and like being photographed by him because he treats them as individuals. Lily Cole asked him to photograph her nude recently, with ethereal results. Teller is the feminists’ friend. “Women are the stronger sex,” he says. He hates photography that objectifies women’s bodies. “That’s insulting, degrading,” he says. He spurns body fascism, thinks beauty comes in many forms – fat, thin, young, old. He doesn’t flatter or embellish, wants to find the truth beneath the skin; his warts-and-all approach is celebratory rather than exposing.

He says he has confronted everything good and bad about himself, believes therapy can make you a better person (he cringes: “I don’t want it to come over like I’m preaching!”). He has the arrogance of all successful artists but claims he’s content in himself these days. There are several reasons for this newish peace of mind. One is his having dealt with his own childhood. Another is having become a father himself.

He has two children: Lola, 10, with his former girlfriend, the art director Venetia Scott, and Ed, 3, with Sadie Coles. Lola lives with her mother down the road and comes by every day: the steel kitchen cabinets are covered in neatly aligned drawings and paintings by her. He’s proud that he and Scott managed the split well: Lola’s happy, he’s happy, he and Venetia still work together occasionally. And now he has his new family with Coles (as I arrived, she was just taking Ed off to nursery). They have been married for five years: he proposed after six weeks. “I’d never been married before. And I will only ever have one wife. It just made complete sense.”

This personal regeneration fed into his recent project, a series of photographs of the old Nuremberg stadium, where Hitler held his rallies. Now it’s derelict, a place for snogging youngsters and kids on bikes; Teller has been fascinated by it since he was a child. His images are close-ups of the weeds growing up through the stones, small signs of hope. He won’t live in Germany again, he says. “I love London. I love the generosity of the English, the lack of judgmentalism.” Maybe this is true in Ladbroke Grove. He’s still baffled by English prudishness. Has he never been self-conscious about his body? He shakes his head. “In Germany, it’s just what you are. And we had a sauna.” He has one in this house, too. And an outdoor shower.

He meant to wear clothes for the Louis XV shoot, but what arrived via stylists was too tight. He squeezed into a pair of silver running shorts (the mind boggles). Then after a while he and Rampling agreed they might as well come off. Didn’t it feel just a little strange to be peeing into a plant pot in front of Rampling? “Not really,” he says. “It was about trust. And my wife was there. It was almost a sweet thing. If I’d pissed in the corner of the room, that would have been completely different. I aimed it very carefully.”

Hmm. But I do understand why he’s looking forward to their next team effort. He tweaks his beard in that uncly way and looks mischievous and slightly bashful. He’ll be naked again, presumably? “No, not me. Possibly her…

Teller Visions

Works from Juergen Teller’s Nürnberg series and a Lily Cole nude are at Galerist Gallery, Istanbul, May 10 to June 14; www.galerist.com.tr. Eight of his ‘Go Sees’ are in Tate Modern’s Street & Studio exhibition, May 20 to August 31; www.tate.org.uk

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