Are the kings of bad taste really a pair of softies?

When the Farrelly brothers looked out the back of their video truck one morning last spring, they found the streets of South Beach drenched by a tropical deluge. After a big clap of thunder, Bobby Farrelly mused, “You wonder how long it took for people to figure out not to stand under a tree when it was lightning out.”

Peter Farrelly’s answer: “Probably a long time.”

Whatever the odds are of being hit by lightning, surely it’s not more farfetched than the odds of seeing Meryl Streep in a Farrelly brothers movie. “We met her at a luncheon a couple of years ago and she said, ‘I’d love to do something with you guys,’ ” Bobby explains. “And we said, ‘Really?’ ”

The Farrellys’ new comedy, “Stuck on You,” stars Matt Damon and Greg Kinnear as conjoined twins who give up their job as short-order cooks in Martha’s Vineyard and move to Hollywood so Kinnear’s character can pursue his dream of being an actor. In today’s scene, the twins introduce themselves to the multiple Oscar winner, who -- playing herself -- is having lunch at a chic L.A. eatery. Streep recalls seeing the twins in their high school glory, winning a big Thanksgiving football game, with one twin blocking, the other running the ball over the goal line.

Streep’s only problem is with the football terminology. When Kinnear says, “Well, actually it was my brother who scored the touchdown,” she’s supposed to respond: “Well, you threw him a helluva block.” Instead, she frequently says, “You threw him a helluva pass,” an impossible feat, even for the most athletic of conjoined twins.

The idea of the Farrellys doing a comedy about conjoined twins initially inspires a full-throated gasp of horror. But the dirty little secret about “Stuck on You,” which is certainly not part of the studio ad campaign, is that the film shows off a kinder, gentler side of the Farrellys. In fact, while much of the humor of the film, which opens Friday, is inspired by the twins’ predicament, the movie is actually an endearing love story between two brothers. The Farrellys have always combined good intentions with bad taste, but watching “Stuck on You” mix low-brow laughs with warmth and compassion is like seeing the circus clowns walking the high wire when the safety net is far, far away.

As is the Farrellys’ custom, most of the extras in the scene are family members, friends and crew. The two men having lunch with Streep, for example, are the Farrellys’ attorney and an old friend who works at their production company. Inside the video truck are the Farrellys’ parents and Peter’s wife and two kids, who take turns sitting on dad’s lap. Between takes, the brothers break out a wad of dollar bills and play liar’s poker. With the Farrellys, who both live back East -- Bobby in Boston, Peter in Martha’s Vineyard -- there is little pretense. The $55-million movie, made for 20th Century Fox, has the no-sweat feel of a backyard home video.

“Meryl called a couple of times to ask about her part,” Peter explains, “and I think she was appalled by our lack of preparation. We don’t do rehearsals. We just kind of wing it on the day we shoot.”

After a couple of takes, the brothers confer. They decide it would be nice to have a take where Streep plays the scene in a different key. In classic brotherly shorthand, Peter looks at Bobby who looks at Peter who sheepishly points to himself, as if to say, “You want me to talk to her?”

After Peter departs, the camera operator arrives, launching into a lengthy technical explanation (“We’ll use a 40 for this part and then we’ll go to a 50 ... “) of how he plans to shoot the next scene. Bobby gravely gives him a thumbs-up sign.

After the cameraman leaves, I ask for a translation. He shrugs. “We’ve been making movies for all these years and we still have no idea what they’re talking about.”

STUDIO ANXIETY

The Farrelly brothers wrote “Stuck on You” in 1990, long before the string of hits, including “Dumb and Dumber” (1994), “There’s Something About Mary” (1998) and “Me, Myself & Irene” (2000) that have made them a brand name in comedy. As unknowns, their script never got an encouraging word.

“The studios were terrified,” Peter recalls. “Nobody wanted to make it. They thought it was mean. And I’d say, ‘Is it mean to make a movie about people in wheelchairs or who have AIDS or heart disease? Are you saying you can’t make a movie about conjoined twins just because you aren’t one?’ ”

The script languished for years. At one point, after the brothers were on the map, Jim Carrey and Woody Allen were set to play the twins, but no one could meet Allen’s price. More recently, Will Smith read it and had the Farrellys do a polish, but then lost interest. Finally, the brothers assembled the team of Damon and Kinnear. Added to the mix were Eva Mendes (“Out of Time”), who plays a wannabe starlet (when she first sees the twins in bathing suits, she blithely asks, “So, where’d you get this done?” as if they were the beneficiaries of some new L.A. plastic surgery) and Cher, who plays a disgruntled TV star who hires the twins to co-star in her new TV series in hopes of getting it speedily canceled.

For the leads, chemistry was a key issue. In some scenes, the actors wear a prosthetic device that required eight hours of prep before filming could begin. So the Farrellys needed not just two good actors but two low-maintenance talents. Hence the presence of Kinnear, an old pal, and Damon, a fellow Red Sox fan with a rep as an easygoing guy.

“Bill Murray is our all-time favorite comic genius,” Peter says. “But there’s no way we could attach Bill to anyone for three months. It wouldn’t be humane. For a minute, we were thinking of Bill and Garry Shandling and then we realized that Bill would reduce Garry to a trembling bowl of tears in about 20 minutes.”

Asked on the set how Damon and Kinnear were getting along, Peter replied: “I’m not saying they’re sleeping together, but they’re pretty close.”

Unlike previous Farrelly films, which have tested in the 90s with under-25 men, in the 80s with over-25 men, and dropped precipitously into the 30s for over-25 women, “Stuck on You” actually got its best overall scores in early screenings from older women. “They’re shocked, happily I’d like to think, when it takes a pretty sentimental turn,” Peter says.

While this poses a serious marketing challenge for Fox -- how do you sell a movie whose strongest appeal is with the audience least likely to want to see it? -- it represents a surprising step forward in the Farrellys’ comic evolution.

In fact, the film is their most autobiographical work as directors. “It never once occurred to us when we wrote it that there was any connection between these guys and my brother and me,” says Peter, who at 46 is a year and a half older than his brother and does most of the talking for the team. (“Bobby believes there’s nothing the press respects less than accessibility,” he explains.) “But when we started showing our friends the film, they all said, ‘That’s you and Bob. You come from this little town back East, you move to Hollywood, and everyone thinks you’re morons.’ So maybe, subconsciously, it’s really us.”

Seeing the brothers around their father, Robert Sr., a retired Rhode Island family doctor, speaks volumes about the sources of the brothers’ pointed humor. (He appears in the film as a sardonic barfly whose drinking buddy is hit in the head with an errant dart.) Known to all as “Docky,” Dad disguises his affection for his family with the brusque manner of a baseball bench jockey. When Peter had a hole-in-one while golfing one day, he broke into an exuberant celebration, only to have Docky gruffly tell him, “Knock it off. You think no one’s ever had a hole-in-one before?”

“They called him Dr. Dirty Mouth because he was always dropping the F-bomb around little kids,” Peter says. “Let’s just say there’s nothing in our movies that could’ve ever possibly offended our parents.”

In the past, the Farrellys have managed to offend practically everyone else, from advocates for the disabled to performers such as Carnie Wilson and Camryn Manheim, who bashed their last film, “Shallow Hal,” for its portrayal of overweight women. Peter recalls watching Manheim on TV, saying she wouldn’t see “Shallow Hal” if it was the last movie on earth. (“Carnie said it made her cry,” Peter dryly reports, “but at least she saw the movie.”)

The Farrellys have become a brand name for bad taste. In a recent episode of “Gilmore Girls,” Rory Gilmore recounts the obnoxious antics of a boy she knew in junior high, saying “he dissected a frog, didn’t wash his hands and then ate a sandwich. He’s like the lost Farrelly brother.” Even the people who bankrolled their movies have sometimes seemed dismissive. Peter hasn’t forgotten going to the 1994 premiere of “Dumb and Dumber,” only to hear New Line chief Bob Shaye get up and say that he hadn’t gotten into the business to make comedies like that. “I love Bob,” Peter says. “But he never got the movie. After that speech, I had to keep my father away from him.”

Comedians rarely get any respect, which is just as true for the Farrellys as for all the legendary clowns who’ve never won an Oscar or an AFI Life Achievement Award. Even though you can see echoes of the Farrellys’ audaciously vulgar humor in a host of hit comedies, from “American Pie” to “Dude, Where’s My Car?” and “Old School,” their image has become something of a millstone.

In recent weeks the brothers have been producing a comedy, “The Ringer,” about a hustler, played by Johnny Knoxville (“Jackass”), who tries to fix the Special Olympics. The Farrellys say the movie has an important message -- that Special Olympics athletes are more special than anyone could imagine. Though they spent years developing the project and getting the blessing of the Special Olympics, the Farrellys backed off from directing it and insisted their names not be touted in the film’s ads.

As Peter explains: “We didn’t want the movie to bear the burden of everyone going, ‘Oh, so now the Farrellys are making fun of mentally retarded people too.’ ”

AN ANGRY PARENT

While visiting the set in Miami, the one time I saw Peter Farrelly truly unhappy was when he spent 20 agonizing minutes on the phone with an irate father of two conjoined twins who’d heard about the movie on the Internet and was threatening to organize a series of protests.

After the day’s filming was finished, Peter closed the door to his trailer, picked up a borrowed phone -- he may be the only member of the Directors Guild of America who doesn’t own a cellphone -- and made the call, pacing up and down in his stocking feet. Peter ended up doing a lot of listening. The father was especially upset over a scene he’s heard about in which one of the twins has sex with a girl while his brother is next to him in bed, as well as the comic tone of an operation when the twins are medically separated.

“This isn’t about making fun of conjoined twins,” Farrelly assured him. “I’m sure there’s some stuff in there you won’t agree with, but these guys are winners. You have to remember, in a comedy there’s a certain amount of poetic license. This is a Hollywood movie, not the Disney Channel. But I really believe our heart’s in the right place.”

Farrelly ended the conversation by offering to send a copy of the script to both the father and his two daughters, hoping the daughters, who were teenagers, might have a better sense of humor than their dad. But after he hung up the phone, Farrelly was pessimistic. “I want him to like this movie. But look, he has conjoined twin daughters who’ve had 19 operations already. He’s entitled to be worried.”

Should he be? Filmmakers today who squeeze laughs out of sensitive issues will always be in the line of fire. On the other hand, “Stuck on You” is so full of uplift that young male moviegoers may grouse that it’s gross-out deficient. It’s doubtful they’ll be impressed that when the Farrellys needed someone to play a doctor who separates conjoined twins, they hired Johns Hopkins neurosurgeon Dr. Ben Carson, who successfully separated a pair in 1987.

What’s most telling about the conversation with the disgruntled dad wasn’t so much Farrelly’s empathetic tone but that he got involved at all. In Hollywood, when someone from a special-interest group attacks a movie, they usually get passed off to a studio flunky or smooth-talking publicist.

It turns out that the Farrellys have raised $1 million for various charities by auctioning off walk-on roles in “Stuck on You.” One ardent fan paid $100,000 for a small part and an up-front credit. The brothers not only hired a pair of conjoined twins, Lori and Reba Schappell, as technical consultants, but when they learned that Reba was pursuing a career as a country singer, they put one of her songs at the end of the movie.

As I wandered around the “Stuck on You” set, I was struck by how many disabled people were on hand, either as actors, extras or invited visitors. When the Farrellys were teenagers, one of their friends, Danny Murphy, broke his neck in a diving accident and has been a paraplegic ever since. After the release of “Dumb and Dumber,” Murphy, who had become an actor, complained that the brothers didn’t have any disabled actors in their movie. Since then, they have gone out of their way to hire actors who are disabled or mentally challenged, though you’d never catch them using such politically correct terminology.

“Most importantly, Danny told us that disabled actors shouldn’t be sweet, angelic types -- they should be the crazy guys, which is often how they got disabled in the first place,” Peter says. “Now probably one-third of the actors we audition are disabled, and most of them are better than anyone else we see. In fact, we have so many disabled actors in the movie that we have to hide some of them, put them behind a desk or something, so no one would know the difference.”

Murphy has a role in the film, as does Ray (Rocket) Valliere, a developmentally disabled friend of the Farrelly’s who has several prominent scenes as a waiter who works for the twins in their fast-food joint. “Rocket had never acted before, but he’s such a great character that I decided to write a role for him,” Peter says. He visited the set when Streep was working, wowing her and everyone else with his encyclopedic knowledge of movie trivia. After Peter informed him that he would get to share a scene with Streep where she performs an elaborate dance, Rocket exclaimed, “I can’t wait! I want to tango with Meryl Streep!”

When asked about his affinity for disabled people, Peter hesitates, worried that anything he says will appear squishy and self-serving. “If there were a religion that involved the karma of helping people, that would be Pete’s religion,” says Bradley Thomas, their producer and production company partner. “Maybe it’s because Pete had a lot of red lights in his life, struggling to make it for a long time, but he’s more comfortable around people who are handicapped or have had hard luck than he is around people who are doing well. He treats them like regular people, which, let’s face it, most of us don’t.”

A key reason the Farrellys made “Shallow Hal” was to use comedy to illuminate the theme of inner beauty, a message that was lost on most of the film’s critics. Even though “Stuck on You” has yet to inspire any significant protests, the sour reaction to “Shallow Hal” has left its mark. The brothers have become vociferous opponents of political correctness, which they believe has forced most modern comedy into a straitjacket, far from the anarchic spirit of classic ‘70s films such as “Animal House,” “Caddyshack” and “Blazing Saddles.”

When “Barbershop” was attacked for making fun of civil rights luminaries, the Farrellys called Ice Cube to commiserate. “The ruckus that blew up over ‘Barbershop’ should be studied by every university in the country. It’s political correctness gone berserk,” Peter says. “People seem to forget that anyone who picks on a disabled person in our movies is portrayed as the bad guy. In the end, no matter what you do, some people aren’t going to like it. I mean, there were people who were offended by ‘Schindler’s List,’ right?”