Ben Stiller and Jennifer Aniston would be assets to any romantic comedy, but they can’t make this one worth your investment. He plays Reuben, a risk-assessment analyst who — get this — takes no risks himself. Though the nerd marries live wire Lisa (Debra Messing), she screws another guy on their honeymoon. Just when Reuben feels lost, along comes Polly (Aniston), a free spirit who teaches him about salsa dancing (much pratfalling), spicy food (much farting) and ferret wrangling (much Farrelly-brothers-ripping-off). Aniston is too sharp an actress to play stooge (she did the same thing in Bruce Almighty) — she’s squandering the indie cred she earned in The Good Girl. Director John Hamburg, who did right by Stiller in the past by co-writing Meet the Parents and Zoolander, strands him here with toilet gags the Farrellys have long since flushed. Having trapped Stiller and Aniston in a one-joke romance, Hamburg calls out the rescue crew in the form of a top supporting cast. Philip Seymour Hoffman milks more laughs than you’d think possible out of the role of Sandy, Reuben’s best friend. Sandy is a former child star gone to pot and currently starring in a community-theater production of Jesus Christ Superstar, playing the roles of Jesus and Judas. As good as Hoffman is, he is still saddled with the most scatological lines in Hamburg’s script. “I sharted,” says Sandy, telling Reuben it’s a term he uses when “I try to fart and a little shit comes out.” Alec Baldwin also dives into the vulgar spirit of things as Stan, Reuben’s boss, a flashy dresser with a gravelly New Yawk accent and a habit of ending every sentence with “mazel, good things.” Hank Azaria gets the biggest hoots as Claude, the French nudist scuba instructor who seduces Lisa on her St. Barths honeymoon with Reuben, Azaria is a master of accents (I love his Apu on The Simpsons), but here — flexing an alarmingly buff body that screams “extreme makeover” — he manages to make his nakedness hilarious. This is the A team, all right, but they’ve been hired to hoist a marshmallow.