Back to the parlor, friends, for some afternoon tea, followed by doubles tennis and a smashing fox hunt. There's plenty of brandy and cigarettes to go round, plus the usual buffet of glowers and snootiness. Mind your one-liners. Keep that stiff upper lip. We're English after all, and that means we get our jollies from acting proper in the midst of misbehavior. Pip, pip, cheerio! If this folderol sounds as appetizing as a week-old scone, then avoid 'Easy Virtue.' It's a traditional English comedy of manners cut from the same drawing-room drapery as 'Gosford Park' and any Oscar Wilde film adaptation, minus the thematic heft and belly laughs of either. It's a simple, forgettable gambol through the country between the world wars. There are a couple of good lines, courtesy of the source material's author Noel Coward, but the story belongs on the stage, where the dialogue can crackle. On-screen, it feels too diluted, too wispy, too much like great scenes were hacked up to cobble together a so-so screenplay. But for those thirsty for an unchallenging diversion, this may be your cup of tea. The English countryside is lovely, after all, and so are the actors: Kristin Scott Thomas as the cold matriarch Mrs. Whittaker, Colin Firth as her unkempt and uncouth husband and Ben Barnes, looking like a young Billy Crudup, as their dapper son John. John recently married an American (heavens!) who's also a famous race-car driver (stone the crows!) with an accomplished sexual resume (goodness gracious!). What (ital) will (end ital) Mrs. Whittaker think? The American race-car driver is played by Jessica Biel, who must have the most talented agent and publicist in America. Ever since she graduated out of the pious, precious '7th Heaven' series, Biel has been a fixture on red carpets and magazine covers despite landing few leading roles in mostly junky movies. She teeny-bopped her way through the rom-com 'Summer Catch' all the way back in the summer of '01 (remember the days of Freddie Prinze Jr.?). She waded through walls of gore in the 'Texas Chainsaw Massacre' remake, did the bimbo thing in 'London' and 'The Rules of Attraction' and 'Elizabethtown,' and placed herself in the company (but not at the level) of quality leading men in 'The Illusionist,' opposite Ed Norton and Paul Giamatti. Now, at 27, she's entering her Serious Actress phase, with an upcoming role as a stripper (the Oscar-y kind) as well as a primo part in a David O. Russell comedy. But first: Noel Coward. As the quick-witted and comely Larita, Biel proves she's just as comfortable in a satin evening gown as she is in a tank top shredded by a serial killer. Larita meets her hubby's family at the Whittaker estate, where her pep is promptly pulverized by her mother-in-law. Mrs. Whittaker and Larita are women from different nations and different generations who share a common love: John. Unfortunately, neither can live with the other, and 'Easy Virtue' becomes a tedious series of one-upwomanships. Granted, 'Easy Virtue' is more elegant and less hysterical than today's average marital comedy. There's a fox hunt, after all, as well as jazzy, big-band arrangements of the disco tune 'Car Wash' and the pop single 'Sex Bomb.' Why? Why not? The strange musical choice almost breaks the monotony of another cinematic weekend in the countryside. Almost. Thomas flirts with her long-dormant knack for comedy but is too busy clamping her teeth down on her lines to swing for the fences. Firth leaves the foppishness at the door, which is unfortunate. It's left to Biel to provide the dazzle. Instead, she merely glows. She's poised and pretty as a picture but not nearly as adventurous as we'd like her to be. Blame the wafer-thin adaptation by Sheridan Jobbins and director Stephan Elliott ('The Adventures of Priscilla, Queen of the Desert'). What might've been a scrumptious, chocolatey dessert of a movie -- a Coward delite -- is instead a spoonful of lemon ice, faintly sweet, mostly water and not nearly satisfying. -- Easy Virtue (93 minutes) is rated PG-13 for sexual content, smoking and brief partial nudity. 