Entertainment

Rom-com bomb for mom

You could make a fine film about juggling mommy hood and the job — from the UrbanBaby.com message boards. That would have to be a horror flick about woman’s cruelty to woman, though.

“I Don’t Know How She Does It” is, by contrast, a meager one-joke comedy peopled by stereotypes. Sarah Jessica Parker plays Kate, a harried Boston banker who spends the entire movie warming up leftover working-mom gags. Here she is getting into a corporate elevator full of suits with a dozen kids’ party balloons. During a PowerPoint presentation, a sonogram of a fetus shows up. In a business meeting, she has “bouncy house” written in marker on her palm. Etc., etc., et-freaking-cetera.

The “it” of the title is juggling (cue, in the closing seconds, an amazingly self-satisfied line about her occupation being “juggler”), but Kate is the kind of ditz who could get lost in a bathtub. Why does she wait until a video conference is starting to adjust her tights? Why doesn’t she ask her nanny to make a pie she needs for the school bake sale? Why does she suddenly start babbling, on a crowded elevator, that “I make a great turkey . . . my breast is very juicy”? Why must she freak out over everything? Give this lady half a Valium and spare us.

PHOTOS: ‘I DON’T KNOW HOW SHE DOES IT’ FILMING IN NY

The movie’s lowly ambition is to be “The Devil Wears Gerber,” or maybe “Sex and the Citibank,” but it’s got a retro soul. (Some lines, about men who refuse to help with the housework, would have fit right into an episode of “I Love Lucy,” a show that wasn’t even funny at the time.) And its real subject is narcissism. Kate, who has two darling kids and a cool, understanding husband (Greg Kinnear), imagines everyone is talking about her uninteresting dilemmas, all the time.

The perfect blond stay-at-home mothers, or “Momsters,” she imagines, are judging her behind her back (why does she care?) while her best friend, Allison (Christina Hendricks of “Mad Men”), rushes to the defense. All of these people issue their clichés directly to the camera in what director Douglas McGrath imagines to be a flourish of immediacy.

But this affectation (and the usage of animated graphics illustrating what’s going on in Kate’s cluttered mind) is merely an effortful way to make all the whining seem fun. Everyone in the audience has to juggle a job and a personal life, too, so what makes Kate’s chatter about food stains on her clothes interesting? Do we really need to hear, again, that men can’t be bothered to pick up some toilet paper?

Women once were confined to housewifery. They were, apparently, unhappy about this. Then they were limited to low-status, low-stress “mommy track” jobs, and were unhappy about this. Now they hold high-paying, highly stressful jobs, are expected to behave as men, and are unhappy about this, too. You could make an Ingmar Bergman miniseries about female unhappiness, but it isn’t new.

A tumbril remark (“Let them eat cake” being the most famous) is one that makes the peasants think about rounding up the aristos and polishing the guillotines. This is a tumbril movie, even before the cringe-inducing Margaret Mead scene in which Kate and an even richer banker (Pierce Brosnan) delightedly discover the existence of bowling proletarians and drink Bud longnecks instead of their usual martinis.

Yes, Kate has a busy life. She works long hours, is tethered to her BlackBerry and is forced to travel on short notice. But she’s a banker in the land of the unemployed. The movie is annoyingly coy about the other side of this particular teeter-totter, which is a giant bag of money with dollar signs all over it. Kate’s kitchen is big enough to host a polo match. Her nanny is there for her all day. She had to miss her son’s first haircut? Let’s see her net worth.

Kate’s buddy Allison issues facile man-hating truisms, such as one about how a man who leaves his job to take care of his kid is considered adorable, while a woman who does so is called disorganized. Such Woman’s Day-level insights don’t constitute a movie, which is why, in an effort to provide something resembling a plot, the movie gins up a flirtation between Kate and Brosnan’s charming widower. (Can’t rom-coms ever imagine a guy whose wife died could still be a total jackass?)

It then doesn’t know what to do with this idea because it doesn’t want its lead to be judged by all the mommies out there. The good news about “I Don’t Know How She Does It” is that it’s so bad that it’s another ovary-punch to the formula chick flick. Bring on more films like “Bridesmaids.”

kyle.smith@nypost.com