Stuck on You

Bobby and Peter Farrelly will probably always be known as envelope-pushing filmmakers for whom nothing is off-limits, but that reputation comes almost entirely from the hair-gel scene in “There’s Something About Mary.” (“Me, Myself and Irene” was legitimately vulgar, but who remembers it?) They went ultra-P.C. (and got too serious) in “Shallow Hal,” and now they offer up another helping of genteel, albeit unusual humor in “Stuck on You.” In fact, “unusual” might be the best way to describe the Farrelly brothers’ humor from now on, rather than “envelope-pushing.”

Bob (Matt Damon) and Walt (Greg Kinnear) are conjoined twins, bound at the midsection and sharing a liver but otherwise two complete men (four arms, four legs, etc.). Bob is a shy athlete, while Walt is a ladies’ man and amateur actor. They work together at the Martha’s Vineyard hamburger stand on that Bob owns, with their combined, well-choreographed efforts at the grill guaranteeing every meal is ready in under three minutes. They are perfectly happy being conjoined, despite their personality differences, and have made it work for them.

But Walt is restless. He wants to move to L.A. to become a professional actor. Bob is happy staying put, and has panic attacks every time Walt is onstage (since he’s there, too, trying to look inconspicuous). Walt points out that Bob’s long-time online girlfriend, May, lives in L.A., and maybe it’s time they finally met. He is persuasive, and Bob wants to help his brother follows his dream. They go.

In Tinseltown, they meet another aspiring actor, April (Eva Mendes), whom Walt starts dating and who couldn’t care less that he has a brother attached to him. After a chance meeting with Cher (in a self-effacing supporting role), Walt is cast with her in a lame TV crime drama. It seems Cher wants out of the contract and uses her casting options to hire someone she thinks the network will dislike as her co-star, prompting them to let her out of her obligation. But they call her bluff and start shooting the show, instructing the cameramen to always keep Walt at the far left edge of the frame so that Bob is out of sight.

Oh, and May (Wenn Yann Shih). It turns out Bob never told her he was a Siamese twin — and he manages to keep it a secret from her even as they begin dating, with various excuses being made for Walt’s frequent proximity. There’s that Farrelly absurdity, taking the common romantic-comedy plot device in which one lover has lied to the other, and taking it to the extreme. For how could you possibly keep such an obvious thing a secret?

In all their films, the Farrellys have employed an underlying sweetness. Here it is to be found in Bob and Walt’s way of eliminating or disregarding every inconvenience their situation must cause, and to turn them into strengths, even. Their sunny outlook comes from years of refusing to consider themselves unusual, and that positive attitude permeates the film. While everyone notices they’re conjoined twins, only the bad guys make an issue of it. It reminds me of how no one thought it was strange that the family in “Stuart Little” adopted a mouse instead of a child.

Damon and Kinnear are affable and funny. It’s not believable they’d even be friends, let alone twin brothers, but that’s part of the joke in the surreal world of the movie. They have a good comedic rapport and do some excellent physical shtick, too, notably in a fistfight they get into with each other. Seymour Cassel is also very funny as Morty O’Reilly, Walt’s 80-year-old Hollywood agent who is decidedly old-school. (“Cronkite’s gonna have a field day with this!” he says in reference to a news story’s upcoming TV announcement.)

As is their custom, the Farrellys (who share story credit with frequent cohorts and producers Charles B. Wessler and Bennett Yellin) have allowed the film to go to theaters with a running time that’s at least 15 minutes too long. The jokes are hit or miss, with a few too many hardy-har-har, “I’m starring in a one-man show”; “You had a friend over? Where was I?”; “If so-and-so calls, tell her I’m not here” kind of gags between the brothers. But, then again, the world of Siamese twins has not been mined for laughs very extensively in the past, so who can blame the Farrellys for doing all the digging they can? Most of what they come up with is pretty good.

B (1 hr., 58 min.; PG-13, one F-word, a handful of other profanity, a scene of sexuality played for laughs, a lot of sexual innuendo and some crude humor.)