I blame “Sex and the City.”

Now everyone thinks that what it takes — or all it takes — for a story about a bunch of women characters to work is non-stop talk about sex and shoes and a complete absence of boundaries. But this film is missing three key elements of “Sex and the City.” First: wit. Second: interesting, distinctive, believable characters and situations. Third: Conversations that are pleasantly racy and edgy between friends are just plain ewwwwwwwwwww when they’re between mothers and daughters.

This movie manages to be offensive and yet dull and predictable, as phony as a Kate Spade sidewalk knock-off bag and as unoriginal as the ready-for VH1 soundtrack. Does it give you an idea if I mention that there are not one, not two, but three intended-to-be-hilarious dropped cakes? And not one of them is actually funny?

With an apparent complete lack of direction and a fingernails-on-blackboard screenplay, all the talented cast can do is race around in a frenzied ditz-fest.

Diane Keaton plays Daphne the supposed-to-be-adorably ditzy, funkily chic, and hopelessly overinvolved mother of three daughters. The older two aren’t important enough for us to care what their names are, but they are played by the should-fire-their-agents-for-this “Gilmore Girls’” Lauren Graham and Piper Perabo. The youngest is Milly (Mandy Moore), also supposed-to-be-adorably-ditzy, who runs a catering service. Her mother says things to her like “Go talk to that guy, but don’t do that thing you do.”

So, what’s an interfering mother to do? The internet is just sitting there, filled with prospective sons-in-law. So, after a brief intended-to-be-humorous interlude in which Daphne gets stuck on a porn site (I hope Gateway didn’t pay for product placement), she posts a “looking for someone for my daughter” ad and soon enough has 17 would-be-suitors lined up for interviews.

And one musician named Johnny (Gabriel Macht) performing in the bar who rescues her from a volunteer therapist who shows up for an impromptu intervention. Daphne thinks she’s found Mr. Right in Jason (Tom Everett Scott), a successful architect. But the musician goes after Milly, too. Soon she’s dating them both. Two problems here: one, there is no reason to believe that Jason would have any interest in Milly, and two, Milly’s failure to be honest with either of them makes her much less sympathetic. Oh, and there’s also a child who enters the picture who makes a lot of only-in-the-movies, intended-to-be-cute-and-funny-but-completely-synthetic comments. But one of these suitors has a handsome dad (Stephen Collins) who makes Daphne think that maybe it’s her own love life she should be fixing. What she should have been fixing is this tedious, unfunny, embarrassing movie, but I’m afraid it’s as beyond repair as those three smashed cakes.

Parents should know that this movie has some crude language and extremely explicit sexual references and situations for a PG-13 movie, including mother-daughters discussions of the pros and cons of thong underwear and circumcised penises, about oral sex and numbers of orgasms. There are some scanty undies, scenes of internet porn (inspiring a dog to hump the furniture), and a brief “humorous” same-sex kiss. Characters do some social drinking and some drinking to deal with stress, loneliness, and nervousness. There is some insensitive racial and ethnic stereotyping and humor involving a possibly suicidal man in counseling that is intended to be humorous but comes across as offensive.

Families who see this movie should talk about how parents know when to step back from their involvement in their children’s lives. And they should talk about how people who care about each other handle the “off days.”

Families who enjoy this movie may enjoy some of the other (and much better) movies about mothers trying to run their daughters’ love lives, including Next Stop Wonderland and For Love or Money. The two wonderful Gary Cooper movies Daphne likes are Love in the Afternoon with Audrey Hepburn and A Farewell to Arms.