WHAT DO YOU THINK OF WHEN you hear the word Seattle? Starbucks? Grunge? What about Humpfest? If you're unfamiliar with the last of these, you soon won't be, as the real-life amateur porn festival (now called simply Hump!) plays a crucial role in Seattle native Lynn Shelton's witty film, Humpday.
A hit at Sundance, where it won a special jury prize for "the spirit of independence", this sparky comedy takes the idea of a "bromance" to squirmingly ridiculous levels, when the surprise reunion of two old college friends, Ben and Andrew (Joshua Leonard and Mark Duplass), leads to a booze and pot fuelled decision to enter Humpfest, with what they believe will be a boundary-breaking film of them having sex together. They are "straight dudes", so it's not gay, they reason; it's beyond gay. But what will Ben's wife say when she finds out about this "art project"?
The Hump! festival, now in its fifth year, is "very Seattle", laughs Shelton. "Seattle, in general, has a really strong number of sub-cultures, in which people are being very open and explorative about their sexuality," says the film maker. Apparently, it now boasts a thriving BDSM (bondage, domination, sadism and masochism) scene, a relaxed attitude to polyamory and, giggles Shelton, a "cultural centre for sex-positive people". It's a sign of a big cultural shift in Shelton's home town, she says; she does not think she could have made Humpday ten years ago.
"Greater openness in general about homosexuality also helped," she adds, citing the role of cultural icons such as Ellen DeGeneres and Will and Grace in mainstreaming gay lifestyles. "In America, if you're under 35, on the whole, nobody cares. It's just not a big deal. People are more out more easily. I think that all means you can explore these topics in a more open way."
Shelton says she used to believe everybody was bisexual and that "if it wasn't for culture, we would all fall in love with whoever we happen to fall in love with".
Scientific studies have shown this is not the case, however, and she now realises that while women's sexuality can be quite fluid (she also appears in the film, as a bisexual woman in a polyamorous relationship), "it's more of a struggle for the guys, for whatever reason". Ben and Andrew are close, but the idea of getting very close creates a discomfort that runs through all their conversations, reaching its queasy peak in an oddly touching climax that places them in a motel room, stripped to their boxers, camera rolling, wondering how to proceed.
"It always seems to me that straight men in general have more invested in their identity as straight guys than other people do," says Shelton. "Even if they have many gay friends and they're very open minded, they have to be constantly reassured that, 'I am straight. And you know it. And I know it. And he knows it'. For some reason, there's this inner terror of gayness.
"And it becomes particularly poignant when you see it in the context of a platonic friendship. You feel so passionately about this person, you want to connect with them so badly, but if you're a straight guy, hah, what does that mean? It's like there's these ramifications of homoeroticism that really make people uncomfortable."
It is not just the male friendship that is well-observed in the film but also Ben's relationship with his spouse, superbly played by Alycia Delmore.
Shelton, who has been married for 16 years and has one child, brought her own experience to the table, much as she did in the experimental films she made for ten years before turning to features with 2006's We Go Way Back. Although Humpday and her previous feature, My Effortless Brilliance, both feature male protagonists, the early films were all informed by her personal experiences as a woman, she says.
"So I made a film about the psycho-emotional aspects of becoming a mother; I had a miscarriage and I made a whole film about miscarriage, and interviewed other women about that experience. My very first experimental documentary was about women's relationship with their body hair. So, very womanly subjects, right?"
Shelton spent so long mining her own experiences that she eventually felt free to observe other people and be less introspective. She has now made two films about men, but gender is not the central issue for her. Rather, she is interested in "any intimate relationship, both with yourself and in relation to other people".
What is most clear watching Humpday is that Shelton does not have an axe to grind or some feminist agenda to push. She clearly knows that Ben and Andrew are a couple of clowns, but she is never less than affectionate towards them. Nor does she ever descend to the depths of crassness plumbed by Kevin Smith's Zack and Miri Make a Porno. "I wanted to take a very loving approach to laughing at these guys. They're making themselves ridiculous, but I never wanted it to be derisive. I just wanted to show them as they really are." The result could be the most left-field date movie at the EIFF this year.
• Humpday is at the Cameo, on 23 and 24 June, as part of the Edinburgh International Film Festival.
What other people are saying...
"If there were a prize for most outrageous premise at the 2009 Sundance Film Festival, Lynn Shelton's Humpday would be ahead of the pack. For now, though, Humpday will have to settle for being Sundance's early buzz film, its mix of squirmingly uncomfortable comedy, painfully realistic dialogue and bittersweet exploration of ... male friendship and adult relationships winning the love of audiences and potential distributors alike."
"Lynn Shelton's Humpday is a comedic Revolutionary Road for 21st-century audiences."