Boys keep swinging

Tight costumes, false teeth and nipples: life on the set of Spider-Man was full of excitement for the director Sam Raimi and his 'funky' star Willem Dafoe

Everything that Sam Raimi says is followed by a hearty chuckle or a sunny grin: this 42-year-old Michigan-born director crackles with a gee-whizz enthusiasm that illuminates the room. And with good reason – he's just made a Hollywood popcorn movie without forfeiting an ounce of the cheerful panache that has characterised his work since The Evil Dead 20 years ago. Only once during our conversation about that new film, Spider-Man, does the warmth subside, as he entertains a sobering thought. "I know Spider-Man is going to make a lot of money," he says gravely. You couldn't credit him with prescience – the combination of a lucrative franchise and a watertight marketing campaign has ensured that even the Amish will be queuing up to see this one.

But "a lot of money" doesn't really cover it. At the time of writing, Spider-Man has grossed over $223.6m (£155m) in two weeks of its US release, which would not ordinarily be worth remarking upon if this wasn't a rare case of a runaway hit that actually deserves its success. Raimi's offbeat B-movie sensibility has served him well. For all its spectacular computer-generated effects, the pleasures of Spider-Man are largely confined to the little things, such as the film's fidelity to the idea that Peter Parker doesn't stop being a geek just because he gets bitten by a genetically altered spider: he lets out a nerdy "wooo-hooo!" as he swings between skyscrapers, and also has to cope with the premature ejaculations that shoot from his wrists at inopportune moments.

Then there are the soulful eyes of the film's bright-as-a-button leading man, Tobey Maguire. The director stood firm by this inspired casting choice, even as the comic-book egg-heads wept into their antique first editions and flooded internet chat-rooms with complaints. "When the camera gets in close, you can see Tobey's a good person," explains Raimi. "I've worked with other actors and you think: 'There's either nothing going on there, or there's something I don't really like.'" Listen to the man – he made a film with Kevin Costner.

For Willem Dafoe, who plays the villain, the Green Goblin, Raimi and Maguire were crucial to his own involvement. "They aren't the usual suspects," he says. "Sam led me past the film's surface and showed me there was stuff there to play with."

Not that it's King Lear by any means. But Dafoe brings some unexpected shading to the Goblin's prissy alter-ego, Norman Osborn. The character continues, in a minor key, what the novelist Russell Banks has identified in Dafoe's choice of roles as "a conflict between duty and sensuality", most notably in Platoon and Light Sleeper. Osborn cannot conceal his disappointment at his own son, or his weird longing for Peter Parker, which gives Dafoe plenty of opportunity to look tormented – to which his too-tight face is well suited. He also gets to deliver lines such as "A thousand years of evolution and we've barely even tapped the vastness of human potential!" Surely the best of both worlds for a man who once said: "When I was younger, if I had any aspirations, it was to be a great B-movie actor."

Dafoe's power lies in his latent seediness – the sneering biker in Streets of Fire (1984) and the scuzzball psychopath in Wild at Heart (1990) will always be present in his performances, no matter how sophisticated the character might be. It's there in Norman Osborn, too, though the studio tried to stamp it out. "I don't know whether you noticed," he says, "but I had fake teeth. You knew there was something 'off' about me, right?" Were the dentures his choice? He looks both ways, as though preparing to cross a busy road. "No," he whispers. "But here's an example of going along with what you thought was a shitty move by the studio, and turning it to your advantage." Shortly after his initial costume fittings for the Green Goblin, he was sent along to the dentist. "I assumed it was for the Goblin's teeth. I got into the chair and said, 'So you're gonna make me these craggy teeth, eh? They gonna be broken? They gonna be metallic? Whadda we thinkin' about here?' The guy went pale and said, 'No. We're going to make them perfect.' The studio had decided that this multi-millionaire scientist wouldn't have these funky teeth that I have, with gaps between them. I thought, 'They're cleaning me up 'cos they're scared of what I give off.'"

He maintains now that the teeth helped his performance, and you can see his point: when he smiles in the movie, you instinctively hold on to your wallet. But the experience clearly rankles. "I felt they were sanitising me," he hisses.

He shouldn't worry. One of the miracles of Spider-Man is that, with the exception of a final half-hour that descends into an inventory of explosions, the picture has avoided becoming just another homogenous blockbuster. That this modest, goofball adventure wears its colossal budget and audience expectations lightly is attributable largely to Raimi, who talks about the project with an affection and flippancy that you couldn't imagine from James Cameron, who for some years had developed the film.

Raimi is already hard at work on a sequel, so I take the opportunity to enquire after his plans for Peter Parker's maturity. After all, this movie ends with him spurning the advances of Mary Jane (Kirsten Dunst), and he will surely need to lose his virginity soon, before that web-shooting problem gets out of hand.

"We should probably let him have sex in the second one," Raimi concedes. "It'll be interesting how he deals with that drive."

Isn't his rejection of Mary Jane a little cavalier?

"I'll tell you what – if he really respects the girl, perhaps he should've told her that he's a superhero, and then let her make the choice with him about bearing that burden. That might have been a more 2002 way to go. But, you know, he's still a kid."

Something else about the film has been bothering me, I confess: why does Mary Jane appear in one scene in a wet T-shirt?

"Well, it's raining," he says, sweetly and disingenuously.

I know it's raining, I say, but it felt slightly gratuitous.

"Oh. I'm sorry. I guess I didn't count on the cold. A lot of superhero movies are about boy- and girl-watching: these incredible physiques, these skin-tight costumes. This movie turned out to be pretty much all boy-watching, so I wanted to give the boys something to watch." But what do the girls get?

"Spidey! Isn't he sexy?"

I think he's sexier for boys – it's that whole homoerotic hero-worship thing.

"Oh, really? That's sad. So I didn't give anything to the girls? There's a shot with Tobey's shirt off."

But that's the male wish-fulfilment scene, in which Peter wakes up and finds that he's suddenly muscular and well endowed. That's for the boys to identify with.

"Oh, God," he exclaims in mock horror. "You're right! With the next film, I'm gonna try harder to give something to the girls."

You read it here first. Let the chat-room whinging commence.

'Spider-Man' is released on 14 June