Depressed ex-hustler James (Paul Dawson) has two muted joys in his life: making arty mini-DV movies, and soaking up the affections of his devoted boyfriend Jamie (PJ DeBoy). When the couple can't decide whether or not to sexually open up their relationship, they seek the advice of couples counselor Sofia (Sook Yin-Lee), who's so dedicated to sorting out the love lives of others that she's overlooked her own sex life and has never experienced orgasm despite the sweaty efforts of her horny husband Rob (Raphael Barker).

To help her loosen up, Jamie and James invite Sofia to an underground sex club called Shortbus, where young New Yorkers, many of them new-New Yorkers, rural misfits attracted to the vibrance of the big smoke, chew the fat in chill out rooms and have group sex in the main room. The fey MC at Shortbus is serpentine drag queen Justin Bond (otherwise known as Kiki from Manhattan cabaret act Kiki and Herb) and guests include the Hungry March brass band,   lesbians named Bitch and Faustus, and a singing duo called the Wau Wau sisters, who sing while hanging upside down from a trapeze. Also lurking in the decadence is professional dominatrix Severin (Lindsay Beamish) who lives in a storage container and who's never had a romantic relationship.

Shortbus is a new film from John Cameron Mitchell, who directed and starred in Hedwig and the Angry Inch, a film about a Western-Sector Berlin boy who becomes a flamboyant transvestite singer in an American punk rock band after a botched sex-change operation leaves him with an inch of stumpy scar tissue and a mile of angst. As with Hedwig, Mitchell tries to play Shortbus against the grain of its bawdy setup with a persistent - and solidly moral - statement about the importance of love. self-realisation and a sense of belonging.

Yet the film's main marketing point is its surfeit of unsimulated sex scenes, performed by a cast of unprofessional actors, who won their roles after Mitchell advertised for auditions of New York club kids on the internet. Almost the whole first act of Shortbus is a series of XXX-rated jump cuts from one sub plot to another, with everything from auto-fellatio, hard-ons and over-the-bedhead ejaculations provoking substantial audience titillation and uneasy giggling in the theatre for at least the first thirty minutes of the film. Once the action arrives at Shortbus, the sex continues with innumerable panning shots over writhing orgy scenes and yet more fucking and groaning.

Even as Mitchell pursues his gently romantic anti-agenda it's explicit three-or-more-way sex scenes or the appearance of remote-control vaginal vibrating-egg sex toys that move his tale along. Though the film casually presents its hardcore side as matter-of-fact, the fact of the matter is that films that play at the local cinema wouldn't go near this level of ribald, porno-strength visuals and so it's disingenuous when Shortbus' promo material claims that Shortbus is primarily a film that "suggests new strategies for reconciling the unique pressures of post-9/11, Bush-exhausted New York City life with questions of the mind, pleasures of the flesh and imperatives of the heart" then compares the film to Woody Allen's Hannah and Her Sisters. To read this information, you need to open the Shortbus website which requests users to "Open Your Mind ... And Everything Else" before dissolving into a zipper that blinks a lascivious request to "Pull Me" in order to enter to the rest of the site.

Shortbus brazenly uses explicit sex for shock value and visual interest, and the film's marketing has made the absolute most of this, so it's strange to hear John Cameron Mitchell say that his film deoes not "necessarily seek to be erotic" and that the sex in it is just "another brush stroke in the characters' lives". We don't need to see Paul Dawson attempt to self-fellate then come in his own mouth in the film's first few minutes, before we even know who his character is: this is deliberate titillation, not a brush stroke that helps us understand the character. As for the players of the orgy scenes, who have no dialogue and most of whom we only glimpse in quickly panning mid-shots, what do we learn about them from seeing them fucking?   By comparison, the sexually explicit films of Catherine Breillat, though not as fun to watch as Shortbus, are enterprisingly erotic and the sex on screen in her films doesn't jar viewers by blurting into view with this level of chorus line boisterousness, it's a requisite piece of the action.

In interviews, Mitchell has suggested that conservative, censorious Bush-era American culture needs shaking up and that more libertarian approaches to sex in movies is one way to approach this end. But snowjobbing viewers with one fat sex scene after the next won't necessarily work to acheive this end, particularly when the content of Shortbus will see it win only limited art-house releases in a select few big cities in America, Australia and Europe, where audiences tend to not be socially conservative and pro-Bush in the first place.

Furthermore, non-New Yorkers may find themselves a bit alienated by the endless handfuls of anti-depressants, emoting, and handheld DV-cams/Polaroid cameras vacuuming up every inane image in sight in the name of hyper-urban "art". Emotional solace is sought at the float tank centre, the office of the sex therapist or the studio of the local dominatrix, where intimate self-revelatory conversations are conducted at warp speed and apparently on a never-ending loop. Claims of impenetrable depression and a polymorphous delight in rolling around in the ennui of one's psychic dilemmas are things that many people may not be able to empathize with.

However, despite these prickles the film is entertaining and interesting and the performances Mitchell draws from his amateur cast are quite impressive. Lee is especially effective, even if at times her moon-faced dreaminess reminded me of the marionette freedom-fighter Sarah out of Team America.

Some of the set pieces are beautifully rendereded and the unexpected appearance of a jaunty brass band late in the film is a wistful and romatic touch. John Bair's 3-D animated New York is a cute and effective device, but only reminded me of what a fantasy scape New York has become, for the many earnest young Americans who flee there every day from rural and suburban upbringings seeking success and sensation in a place that exists only in their imaginations.