Owen Wilson single-handedly hauls this amiable, middle-of-the-road comedy out of sheer mediocrity. It's about newlyweds whose marriage is shaken by the antics of a professional slacker who's neither as dumb nor as hapless as he makes out. Flying in the face of the axiom that all comedies end with a wedding, this one opens with a no-expense-spared Hawaiian bash thrown by egocentric real-estate mogul Mr. Thompson (Michael Douglas) for his little girl, Molly (Kate Hudson), and Carl Peterson (Matt Dillon), the drone who somehow snared the boss' daughter. And wouldn't you know, the first moment the couple manages to steal for themselves is interrupted by Dupree (Wilson), who isn't even there. He somehow managed to make his way to the wrong island and, having hitched a ride on an inter-island puddle jumper, now needs to be picked up at an isolated, cargo-plane airstrip. Before the wedding is over, Dupree has wheedled a customized groomsman's shirt out of Carl; laughed immoderately at Thompson's toast to his new son-in-law (a masterpiece of emasculating insinuation masquerading as good-natured, "just kidding" humor); and initiated a juvenile drinking game that ends with Carl's pal Neil (Seth Rogen) in flames. And there you have Dupree: Careless, self-centered, irresponsible, so slyly manipulative that if he redirected his energies he could make a go of damned near anything. But then he wouldn't be the free-spirited adventurer, the wild-and-crazy life of the party, the canny opportunist who knows just when to dial down the hell-raising and trot out the rueful tales of woe and pound-puppy eyes. When Dupree ends up homeless — he lost his job for taking time off to attend the wedding, don't you know — Carl invites him to sleep on his and Molly's new leather couch for a few days while he gets back on his feet. Dupree proceeds to wreak havoc with a bashful smile, his mere unruly presence driving a wedge between Molly and Carl even before Carl starts working until all hours on the dream project Mr. Thompson is systematically sabotaging. Screenwriter Michael LeSieur undermines his own setup by making Thompson into a creepily possessive dad determined to ruin his daughter's marriage — Dupree's goofball machinations are the main event, and anything that detracts from them is excess baggage a 108-minute comedy doesn't need. Directors Anthony and Joe Russo show no particular flair for slapstick comedy, but Wilson's effortlessly impeccable timing almost saves the day.