But, you know, if you found a cockroach in your Zesty Blackened Heterosexual Manly Burger, you’d complain about it anyway.

There’s more than a few cockroaches here.

The notion is that four couples, friends all, verging on middle-age head to a romantic paradise resort for a vacation that turns out rather differently than they’d planned. (Actually, it’s only the 40ish guys and one of the women who are verging; three of the four women are 10 to 20 years younger than their partners, but that’s so tediously “normal” for Hollywood that it’s barely worth bothering over here. It’s certainly the very least of the movie’s problems.) Jason and Cynthia (Jason Bateman [The Invention of Lying, Extract] and Kristen Bell [Forgetting Sarah Marshall, Heroes]) are considering divorce, and need the resort’s couples’ therapy program to help them decide. But they can only afford a visit at a group rate, so they connive Dave and Ronnie (Vince Vaughn [Four Christmases, Fred Claus] and Malin Akerman [The Proposal, Watchmen]), who are very happily married, Joey and Lucy (Jon Favreau [G-Force, I Love You, Man] and Kristin Davis [Sex and the City: The Movie, The Adventures of Sharkboy and Lavagirl in 3-D]), who are secretly near to the point of murdering each other, and divorced Shane (Faizon Love: The Perfect Holiday, Elf) and his new 20-year-old girlfriend Trudy (Kali Hawk) into coming along.

It’s all actually far more painfully contrived than it sounds. The script, by Favreau, Vaughn, and Dana Fox, is rife with plot devices so thoroughly implausible -- even grading on the instantly-forgettable-multiplex-fluff scale -- that you have to ask, If it was necessary to invent such awkward absurdities in order to get the story in motion, perhaps this story simply was not worth telling. (It’s agonizing to see how Favreau has squandered his talent as a screenwriter: his scripts for the indies Swingers and Made are brilliant.) A scant few of the emotional details of the couples’ relationships are genuine: Jason’s despair as he explains to Dave how he and Cynthia’s attempts to get pregnant have taken all the romance out of their marriage is authentic (kudos to Bateman, though he is left for the rest of the film to flounder as a control-freak stereotype); and Vaughn is suprisingly appealing as a cheerful dad to two small rambunctious boys.

But once the movie arrives at the couples’ resort, any pretense to sensibility or emotion is thrown out the window. The film’s funniest line -- just about the only one, in fact -- is Joey’s reaction upon seeing this tropical paradise: “It’s like a screensaver.” But it’s much less funny when you realize that the movie appears intent on being much the same: not pretty to look at (though it is that at arbitrary moments to which no thought appears to have been given by first-time director Peter Billingsley [yes, Ralphie from A Christmas Story]) but a random selection of unrelated pieces gathered in one place for your purported amusement. Now it’s a sendup of touchy-feely therapy; now it’s a humiliation fest playing off the assumed juvenile discomfort of the audience with nudity and sexuality; now it’s a would-be feel-good paean to the ups and downs of marriage and committment. But if there’s a fun movie to be spun out of listening to couples bicker -- for you do realize, don’t you, that even the happy couple will be tried by their experience here? -- this is not it. I might have expected that Favreau could write such a movie, considering how wittily observant his early screenplays were, but he hasn’t.

Alas that the same complaint -- that a movie tries to hit too many notes and ends up missing them all -- can be applied to too much of Hollywood’s output these days, especially with movies meant to be comedies. But there’s a special clumsiness to Couples Retreat that elevates it to its own realm of crass obscenity that is perhaps best exemplified by its outrageously awful attempt at product placement. I won’t dignify the product by identifying it, but its name gets dropped early in the movie, and you don’t realize that it’s a gun sitting on the mantelpiece till it shows up again, in the last place you’d expect it, doing the last job you’d expect it to do. (I suspect Favreau and Vaughn and Fox thought this unexpectedness would render the concept funny. It doesn’t.) If previously I might have been willing to chalk up the all-over-the-place messiness of the movie to simple incompetence, now I had no choice but to see it as deliberate and calculated, an attempt to pander to as many segments of its potential audience as possible.

It’s as if the cockroach in the burger were put there intentionally, in the bizarre hope that you’d enjoy the extra crunch.