The sex is real in John Cameron Mitchell's Shortbus; only the setting—an animated New York cityscape, watched over by a fluorescent Statue of Liberty—is fake. To an extent, that describes the movie: a sexually daring, dramatically timid roundelay that employs unsimulated twosomes, threesomes, and even solos for skin flute in the service of subplots reminiscent of late-night-cable soap. Yet there's something refreshingly frisky and celebratory about Shortbus that offsets its flaws. It's a triple-X midnight movie with a heart of squarest gold.
In the jazzy opening sequence, cut like a musical-comedy overture, the camera flits among a bomber crew assortment of proclivities: Hunky ex-hustler James (Paul Dawson) attempting to suck himself off, a hetero couple banging away at a piano, a morose dominatrix (Lindsay Beamish) silencing her rich-kid client's inappropriate small talk ("Do you think we should be in Iraq?") with a few surly lashes.

Everyone seems to be getting off except Sofia (Sook-Yin Lee, a Canadian TV personality destined for one hell of a Q rating). Frustratingly "pre-orgasmic" with her husband, Sofia throws herself into her work, sex therapy; her patients include James and his longtime lover Jamie (PJ DeBoy), another couple whose relationship has hit the wall. At their urging, Sofia crosses the vanilla-sex Rubicon into the domain of Shortbus, an orgiastic Brooklyn lounge where gender is fluid and anything goes.

"It's like the '60s, only without hope," intones pansexual ringmaster Justin Bond (the champion scene stealer, two parts Dietrich to one Joel Grey) in the movie's instant catchphrase. Or the '70s, without ignorant bliss. When Deep Throat made its unprecedented conquest of legit audiences in 1972, cineastes hoped it would blow away the Hays Code's prudish residue and give Hollywood a mandate to explore the gray zone between art and obscenity. A decade later, Last Tango in Paris yielded to Porky's.

Working with characters who pack considerably more than Hedwig's angry inch, Mitchell wants to party like it's 1973. Or at least he wants the same thing as those adventurous moviegoers—explicit sex treated as a facet of shared existence rather than taboo raincoat material. Mitchell's cast of fresh-faced fellators and fetishists could pass for a touring company of Rent. Or think Friends, only with Ross felching Joey. For its first half, Shortbus succeeds in doing the nearly impossible, fusing hardcore to light comedy without losing either its raunchiness or lightness. If anything, its mostly unfamiliar actors—who, in the 42nd Street (or pre-Giuliani 42nd Street) tradition, are going out nobodies and coming back stars—perform less self-consciously with their genitals than with their soul-baring dialogue.

In its somber second half, though, Shortbus starts to creak. The problem isn't that the film becomes serious; it's that it has such a limited idea of seriousness (goopy psychodrama, suicide attempts). The attempt to convey character through sexual activity is admirable, but watching the group through sex goggles alone eventually filters out almost everything else that's interesting about them. Linked by their inability to feel, Sofia, the dominatrix Severin, and James are reduced to suitable cases for treatment with only one solution. The boisterous happy ending that administers sexual healing has the contrived insistence of a public service announcement—a resolution as safe as the sex is transgressive.

As with Brokeback Mountain, though, it's not the sexual content that seems revolutionary; it's the mainstream friendliness. That friendliness is a double-edged blade. In distinguishing his experiment, Mitchell has explained that porn merely wants to arouse. Fair enough, but part of the openness briefly promised by porno chic involved getting audiences to own up to their prurient desires: Why exactly am I here watching a dirty movie, and why am I responding? Shortbus ultimately makes it too easy for viewers to convince themselves they're reading a strokebook for the interviews.

At the same time, given the recent cinema's track record of unfaked hate sex (Baise-Moi), diseased sex (Anatomy of Hell), or just plain lousy sex (take your pick), Shortbus's messianic sex-positive cheer seems more startling than its straight-up intercourse. Even with the phantom presences of ground zero and AIDS—among the Shortbus clientele is a doleful Ed Koch look-alike haunted by the epidemic—Mitchell's Brooklyn hot spot holds the same allure that Manhattan always had in old musicals: It's a beacon of cosmopolitan self-invention. Shortbus celebrates New York as the melting pot of smut. In what should be the movie's most outrageous scene, Jamie, James, and their boy toy Ceth (Jay Brannan) spontaneously erupt into "The Star-Spangled Banner" during a convoluted three-way, using each other as human bullhorns. It sounds like a sneering provocation. But in performance, it comes off unironically jubilant, even patriotic—is this a great country or what? As long as one man remains free to sing the national anthem into another man's asshole, the terrorists haven't won.