‘The Big Wedding’ Review: Ho-Hum Ceremony With a Lively All-Star Guest List

This nuptial farce is the kind of film best enjoyed while on the couch, zonked out on cold medicine, secure in the knowledge that it won’t make you any sicker

If you were shying away from “The Big Wedding” because (a) it has the word “wedding” in the title; (b) the cast includes Katherine Heigl and/or (c) the cast also includes Robin Williams as a Catholic priest providing marriage counseling, thus calling to mind his similar role in the wince-inducing “License to Wed,” well … those are all actually valid points, come to think of it.

Still, in its defense, it’s worth noting that this farce is funnier (and naughtier) than it has any right to be, and that Heigl gives her most winning performance in years — precisely because she’s playing a rage-filled character and not a simpering romantic lead.

Even Williams dials it down a notch or 10 and plays well with the film’s staggeringly all-star cast, all of whom do the heavy lifting to make this piffle at least marginally entertaining.

“The Big Wedding” isn’t great, but it’s not horrible, either. It’s the Jordan Almond you eat at the reception not because it’s tasty but because it looks pretty. It’s the sort of movie best enjoyed while on the couch, zonked out on cold medicine and secure in the knowledge that it won’t make you any sicker.

Writer-director Justin Zackham, adapting the French comedy “Mon frère se marie,” establishes its R-rated credentials early on, with Ellie (Diane Keaton) accidentally walking in on her ex-husband Donald (Robert De Niro) as he’s about to begin orally pleasuring his longtime girlfriend Bebe (Susan Sarandon). Ellie has returned for the wedding of her and Donald’s adopted son Alejandro (Ben Barnes, “The Chronicles of Narnia: Prince Caspian”) to lifelong friend and neighbor Missy (Amanda Seyfried).

As in any farce or big family occasion, there are plenty of mini-dramas going on besides Ellie and Donald’s awkward reunion; their daughter Lyla (Heigl) has just kicked out her husband (Kyle Bornheimer), while their son Jared (Topher Grace) is a 29-year-old doctor still holding out to lose his virginity to his true love.

On top of that, Missy’s WASPy parents (Christine Ebersole and David Rasche) clearly have issues with their daughter marrying a Colombian.

Compounding the craziness is the impending arrival of Alejandro’s biological mother Madonna (Patricia Rae), visiting the U.S. for the first time. Alejandro worries that her intense Catholicism will make her object to his adoptive parents’ divorce, so he asks Ellie and Donald to pretend like they’re still married until the wedding is over. (Along for the ride is Ana Ayora as Alejandro’s sister Nuria, who seems like she might be the perfect candidate to end Jared’s dry spell.)

Once the plates start spinning, there aren’t a lot of surprises, but the presence of so many old pros injects a great deal of life into “The Big Wedding.” Shockingly, this is the first time Sarandon has worked with either Keaton or De Niro, but the three of them mesh beautifully, fully convincing as a trio of old friends (Ellie and Bebe were best pals before Bebe and Donald hooked up) and carting in lots of characterization that would be otherwise lacking in Zackham’s rote screenplay. (His major previous credit was writing the hoary “The Bucket List.”

Given the tame PG-13 age in which we live, there’s something to be said for a movie owning its R rating and letting big stars get a little bawdy. The charge of seeing Keaton (delightful throughout, particularly given her recent run of duds like “Mad Money” and “Because I Said So”) talk about nine-hour orgasms or Heigl letting De Niro have it with both barrels for his wastrel-ish ways gives the movie some much-needed zing.

Put it in your TiVo, and save it for flu season.