"I mean none of us wore clothes -- ever. I've never had to do more humiliating stuff than I had to in This Life. It got to the point where we would all dread being given our scripts," he says.
Seventeen years on, the 39-year-old still can't quite understand why Amy Jenkins's series -- a cynical but true-to-life British Friends that captured the Nineties Zeitgeist -- was as popular as it was. Or why Miles, an arrogant trainee solicitor and his love-hate relationship with fellow lawyer Anna (Daniela Nardini) gripped viewers.
"It was my first real job and the show gathered this mad momentum.
"It's true that it was very well written and, crucially, both unpatronising and unmoralistic -- people took drugs and didn't die; people slept around and didn't die -- but I didn't really understand why we were on page five of the newspapers every other day.
"I was a bit freaked out at the time and I remember my father taking me aside and saying: 'I don't mean this in a bad way, but this might be as firestormy as it gets for you'."
Until recently his father, the actor Nigel Davenport, seemed to have been proved right. There was the short-lived BBC series Couplings, what was supposed to be his "breakthrough" role in Anthony Minghella's The Talented Mr Ripley, and his recurring role as James Norrington in the Pirates of the Caribbean films. But it wasn't until Davenport was reborn as the narcissistic Broadway musical producer Derek Wills in Smash -- Steven Spielberg's brilliant but slow-burn TV drama on Sky Atlantic that has been billed as "Glee for adults" but is more like a modern Fame -- that our interest in "Miles'' has been rekindled.
When Davenport joined his mother, the actress and theatre director Maria Aitken (sister to Jonathan) and stepfather, the writer Patrick McGrath, in Manhattan more than a decade ago, he was heading for the "whatever happened to?" category of actor. What happened was a series of promising television roles in US dramas (the most notable being Swingtown in 2008 and FlashForward in 2009, neither of which made it past the first season), marriage to his wife of 12 years, Michelle Gomez (the sociopath from Green Wing) and the arrival of a son, Harry, a little over two years ago. All of which explains why we are sitting in a gourmet coffee house in Brooklyn's nappy valley, drinking lattes
He is tanned and lanky, folding himself into an armchair with an appealing British awkwardness, and it's easy to see why, beneath Wills's dastardly disguise, his public schoolboy good looks (two parts Greg Wise to one part Hugh Grant) might set the local yummy mummies aflutter. "I don't get recognised that much in the street," he assures me.
Perhaps because of that early brush with fame, Davenport has had an uneasy relationship with celebrity. He once said that "being a good actor is about doing a disappearing act". Does he stand by that now that Smash is likely to make him a household name on both sides of the pond? "I do," he says earnestly, "even though I know that it's an old-fashioned position."
When he and Gomez, with whom he fell in love when he repeatedly went to see her in the stage version of Trainspotting -- were asked to sell their wedding to a weekly gossip magazine, Davenport was appalled. "I couldn't believe it. And yet there are people who will do whatever is necessary to keep a public profile. But in order to do my job properly it's important for people not to know too much about me."
It is both a cliche and a lie that most actors do what they do for love of their art (fame being an unfortunate side effect) but Davenport's assurances ring true. "Honestly, I do this job because I love it. Even as a child, it wasn't about wanting to be famous. It was about wanting to be a part of this tribe. I grew up in Suffolk and Ibiza, surrounded by actors - they were fun and playful and I wanted to be one of them."
Although his parents tried to dissuade him, Davenport refused to be dissuaded. "They were both working a lot but they didn't want me to be fooled into thinking that it was all roses. I remember them constantly telling me that, at any given time, 90pc of actors aren't working."
Davenport is one of the fortunate 10 per cent. There have been lean spells, he admits, but basing himself in the US made a difference. "A lot of the British actors who have made it out here have just stuck around. Because in this profession there is always an element of right place, right time."
When Davenport landed Smash, and the phone call from Spielberg actually came, he was duly deferential. "I managed to hold back on calling him Steve," he jokes, "but it was disarming how charming he was. He'd seen all the rushes and I thought 'I suppose that's why you're you and I'm me'."
The producer, the theme and the cast - Anjelica Huston, Katherine McPhee, Uma Thurman and Debra Messing - drew Davenport to the project from the start, and he is fiercely defensive of his character.
" I guess it depends how you feel about workplace relationships," he laughs, referring to Wills's womanising.
Did his wife mind him working his way through every beauty in the cast? "Believe me, I've had to sit through my fair share of her doing unspeakable things with relative strangers. But my wife is an accomplished actress and we're both very aware that on-screen sex scenes are like playing Twister."
There is a second series in the making but Davenport is wary of sounding too confident. "Television is pretty Darwinian: nothing is ever a slam-dunk." Still, he is not surprised by the all-singing all-dancing show's success so far. "Everyone on a visceral level is a sucker for watching beautiful young people do something incredibly difficult very well."