There are a lot of ways for a man to scare off an interested woman. One might be to say, ''Babe, this isn't working for me." Another is to stop calling her. Meaner, I'll admit, but it works. Tripp, the tanned Casanova Matthew McConaughey plays in ''Failure to Launch," tries another tack. When things get too close with a potential girlfriend, he takes her home to meet his parents.
Lest you get carried away by the promise of romance in that gesture: Tripp's parents are also his roommates.
Still, the hilarity in this sunny movie comes from a twist in the plot that occurs not long after he meets Paula, a more-than-meets-the-eye ''special needs" consultant whom Sarah Jessica Parker plays with superhuman breeziness. She and Tripp have a lovely meeting in a Maryland furniture store, where they recline in Barcaloungers and make a date for dinner.
For about six years, Tripp's mother, Sue (Kathy Bates), has been cooking his meals, washing and folding his laundry, making his bed, and tossing him a snack on his way out to his job as a boat salesman. She even vacuums the sinfully upscale bachelor pad that is his only-in-the-movies bedroom. Written by Tom J. Astle and Matt Ember and directed by Tom Dey, the movie makes sure we know early on that Sue and her husband, Al (Terry Bradshaw), are tired of pampering their 35-year-old son. At a cookout, they discover how some friends recently got rid of their kid. They hired Paula.
Time magazine covers, entire swaths of Newsweek, and half a dozen morning-news segments have covered men like Tripp to death. Time even popularized the term ''twixters" to describe them, a word so stupid that it should have inspired adult moochers to leave mom and dad's as a matter of embarrassment, killing the trend. Sue and Al's determination to drive Tripp from their home and Paula's arrival enliven this TV setup.
''Failure to Launch" is an actual situation comedy that's cleverly post-sitcom. The television show would have been all about a dude who moves in with his parents. Period. The movie holds on to the parents, the dude, and his buddies, a nature-boy slacker (Bradley Cooper) and a lovable techie (Justin Bartha), neither of whom have anything in common with Tripp except that they live with their folks, too. But the movie is surprisingly nimble and emotionally honest, with particular respect to Sue, who's ambivalent about wanting Tripp to leave for touching reasons.
The movie brings to mind the more polite parts of ''Wedding Crashers." ''Failure to Launch," while totally exuberant and appealingly made, is not nearly as randy. The camera does find it impossible, though, to resist gaping at McConaughey's bare chest or open shirts. The man is sure to come back as a muscled-up, well-oiled peacock in his next life. (Incidentally -- and ill advisedly -- wildlife is employed to attack Tripp out of his comfy living arrangement. Please don't ask.)
In any case, the film is also surprisingly well cast. Who knew, for instance, that Terry Bradshaw could be as goofy and affectionate with Kathy Bates as he is with James Brown and Howie Long on ''Fox NFL Sunday"? The wonderfully dour Zooey Deschanel has no business playing Parker's best pal and housemate, Kit. (How are these two friends, exactly?) But it doesn't matter; she bends the implausibility to her deadpan will, making the most of a belabored plotline involving a mockingbird that needs killing.
If there's a real problem with ''Failure to Launch," it's Paula's job, which at moments forces her into situations that play a lot like prostitution. But Parker glides through them like, well, a professional. Romantic comedies are better with her in them. ''Sex and the City" has prepared her for any type of man and every brand of romantic contrivance. She's snappy, smart, and, on this occasion, luminous, too. For a McConaughey movie, this is unusual; she's the rare actor not upstaged by the numerous shots of his cleavage.
Wesley Morris can be reached at firstname.lastname@example.org.