"It's Complicated" is lying from the moment the title appears.

Writer-director Nancy Meyers' latest relationship comedy isn't what the name promises at all. It's simple, almost as simple about grown-up romance and heartache as the average Hollywood teen comedy is about youthful love and sex.

That said, a simple-minded story can benefit enormously with Meryl Streep on screen for almost an entire movie.

Streep follows her delightful turn as Julia Child in "Julie & Julia" and sparkling voice work in "Fantastic Mr. Fox" with a charming performance as a divorced woman in an affair with her remarried ex-husband (Alec Baldwin) and a flirtation with a new man (Steve Martin).

It's got to be hard, hard work to bring authenticity to a character as potentially artificial and shallow as Streep's Jane Adler. Streep makes everything look effortless and real these days: singing, dancing single mom in "Mamma Mia!" over the summer, stern, inflexible nun in "Doubt" come winter.

She probably could have played one of the 10-foot-tall, blue-skinned aliens in James Cameron's "Avatar" in curlers and a housedress and made it seem as genuine without any of the elaborate digital enhancements used to top off that film's stars.

Too bad Streep has to put on this nice show to such superficial effect in "It's Complicated," and for that matter, too bad for Baldwin, Martin and the rest of an earnest supporting cast led by John Krasinski.

Meyers serves up fluff as light as the pastries Jane bakes for a living, a story to make divorced people wish their broken marriages and the ugly aftermath could be as fun and frolicsome as this.

Ten years after Jake (Baldwin) left her, Jane has reached an uneasy peace with her ex, who's now married to a younger woman (Lake Bell).

With three grown children (Caitlin Fitzgerald, Zoe Kazan and Hunter Parrish) and a rock-steady future son-in-law (Krasinski), Jane has put her life back together comfortably, serenely. She runs a successful bakery and restaurant in California and has a gorgeous house that she's about to turn into a palace with additions and modifications.

Then bam! Jane and Jake find themselves alone over dinner and many drinks at a hotel in New York City, where they and the rest of the family have gathered for their son's college graduation.

Sparks are rekindled, a rash one-nighter leads to an affair, and Jane finds herself wooed by Jake, who's dissatisfied with the new wife and wants the old one back.

And wouldn't you know it? This happens just as Jane and her divorced and lonely architect Adam (Martin) start taking an interest in each other.

Even with Streep and Baldwin's drunken-debauchery scene, the first half of the movie is deadly dull, lingering scenes of uninteresting chatter, lame coincidental meetings between Jane and Jake, and annoying girl-talk sessions among Jane and her pals (Mary Kay Place, Rita Wilson and Alexandra Wentworth).

The film stutter-steps to life now and then, particularly during Jane and Adam's date on a good marijuana buzz. Mostly, though, Meyers lets her stars mince about to varying effect.

In Streep's case, that may be enough on its own to justify the price of a ticket. In Baldwin's case, it's a tossup. Sometimes he's funny as he jealously stalks Jane, other times he mugs along in a toothless imitation of the overbearing self-absorption he does so well on "30 Rock."

The big laughs Meyers swings for never pay off the way she wants, and the three-way romance totters to an uninteresting conclusion that lacks anything approaching the heart of how her love triangle wrapped up in "Something's Gotta Give."