There's a reason why audiences rarely receive mother-son comedies with gusto: Most of them rely on tension around control — all family stories do, to an extent — and most sons don't like to return to the time (that is, childhood) when their moms ran things. Watching a grown man ward off guff from his mother, as Seth Rogen does in "The Guilt Trip," an affable if largely unfunny comedy, crumples the viewer's masculinity into something the cat could choke down in two bites. It's emasculation by proxy, even if by the film's end you wind up somewhere worthwhile.
Vaguely we want to like this son, and vaguely we see that, at heart, maybe he's not really a condescending snot. But he's that in spades during the first two-thirds of "The Guilt Trip," as he forces himself to adopt a front of politesse against his mother, Joyce, a doting (Jewish? It's never made explicit) mother from New Jersey. Barbara Streisand plays Joyce, in her first movie without the word "Fockers" in the title since 1996. She's strong and funny enough here to make 16 slow years seem like comedy's loss.
Andy is a chemist who's visiting big retailers to pitch a clunktastically-named cleaning product he invented. His pitch is awkward, too stubbornly technical, and he's down to his last few hundred bucks when he arrives in New Jersey to see his mom, a widow in a permanent romantic funk. She's loud, attention-hungry; only her obvious good intentions rescue her from the brink of obnoxiousness. Joyce blames herself for Andy's lack of romantic success and confides in him that she once had a love, before Andy's dad, with whom she lost touch. Andy does a bit of Googling on the sly, locates the fellow in California, and proposes to Joyce that she come along on his cross-country sales trip, which he says now includes a meeting in San Francisco.
So here is your odd couple, overbearing mother and reluctant son, stuffed in a rental compact for the width of the United States. Joyce eats M&Ms loudly in bed and insists on listening to "Middlesex" in the car; Andy, riding a string of rejections, gets increasingly condescending and fussy. And it's in this first long stretch (approximately Jersey to Texas) that we come to quite dislike sitting in the car with these folks. She is endlessly talkative and cannot ask a question without also foisting advice upon him, while he is so frustrated at being treated like a child that he begins acting like one. Say this for "The Guilt Trip," at least: It's incisive. Releasing it this time of year was an act of holiday daring. Look around, if you go, and try to notice parents and grown children writhing for the first hour. Then picture them staring ahead in silence once they get onto the highway themselves.
Once an event in Texas forces the mom and son to clear the air and begin talking to each other with honesty and kindness — well, that's when this comedy actually starts to get funny, and even heartfelt. Director Anne Fletcher ("The Proposal") seems to drop the reins a bit and let her stars riff. A theory: Rogen and Streisand really do like one another, and have some chemistry on-screen, but having to play enemies really didn't suit them. (He should've just listened to his mother the whole time!) The bet here is that mothers will enjoy "The Guilt Trip" more than their kids, but then, that's usually the case.