Couples Retreat; PG-13, 107 minutes; Opening Friday

Early on in Couples Retreat, Vince Vaughn’s character finds himself in a housewares store, where his young son has used a toilet meant for display only. “There’s not a lot to say,” Vaughn forthrightly tells a galled store clerk, by way of apology. That’s pretty much what it’s like to review Couples Retreat. When confronted with a cute, exasperating, innocently impolite public expression of bodily function, the strong temptation is just to let the act speak for itself and quickly withdraw.

But that might seem lazy, so here’s more.

Package deal: Carlos Ponce (left) gives Vince Vaughn and Malin Akerman advice on their marital unit in Couples Retreat.

After a brisk couples-through-the-ages montage and many long and leaden minutes of setup (not a lot to say, apparently, but much to do), four couples come to a tropical resort, where their collective vacation briskly becomes many long and leaden minutes of marriage-repair therapy. One of the couples—it doesn’t matter which—has been on the verge of divorce, and the only recourse was to drag the others along for some “skill-building” on the beach at the more affordable group rate. Well, you get what you pay for.

This may sound like the pretext for a torture-porn horror thriller, and some audiences may well see it as such. What it’s supposed to be is a romantic comedy of classical appeal. What it is, really, is more like a half-assed update of Fantasy Island, somehow both shriveled to short-sitcom proportions and bloated to feature-film length.

The director is Peter Billingsley. The stars are Vaughn and Jon Favreau (who wrote the script together, with Dana Fox), Jason Bateman, Faizon Love, Kristin Davis, Malin Akerman, Kristen Bell and Kali Hawk. They’re all perfectly easy to like, and just as easy to forget. That also goes for Peter Serafinowicz as their punctilious host, Jean Reno as their “Couples Whisperer” guru, and Carlos Ponce as a buff, inappropriate yoga instructor. Among the plot points, in addition to some boilerplate romantic recriminations, are a shark attack, a Guitar Hero showdown and a general sense of Vaughn and Favreau coming to terms with not being in Swingers anymore.

Even still, Couples Retreat sometimes gives off an air of self-satisfaction. It’s a mild air, like a warm island breeze, and seems to be the natural result of good pals having a good time in a good place making a movie that’s just not good.

Lately, Vaughn in particular has seemed increasingly at ease with squandering his gifts. His way of not being bothered by mediocrity is almost charming of itself, but shouldn’t be rewarded. Real couples in need of retreat from busy but average lives will recognize themselves in his character’s avowal, during that protracted prologue, to “buckle down over these next six months, and then when we come up for air, we’ll go somewhere.” Getting away from it all isn’t easy. Start by getting away from this movie.