Beginning to wonder if there exists such a thing as a functional family? Movie after movie, we meet families so removed from reality that they make the Bobbits sound normal. What ever happened to families like Cheaper by the Dozen’s Gilbreths or the March family from Little Women? Sure, they had their problems, but incest and attempts at fratricide weren’t on the list.

The House of Yes is an film high on audacity that dares to treat such topics as comedy. Of course you’ll laugh, but you’ll probably spend most of your time squirming in your seat. Yes is a jarring movie with plenty of surprises, but the novelty of an incest comedy quickly wears off. The daring soon become dull as this one-trick pony gets going.

Twenty years have passed since JFK’s assassination, and it’s Thanksgiving time at the home of the family most affected by his death. (No, they’re not the Kennedys.) On the night of the killing, Mr. Pascal mysteriously disappeared, and things haven’t been the same since.

A few years before our fateful Thanksgiving night, fraternal twins Marty (Josh Hamilton) and Jackie-O (Parker Posey) crossed a few forbidden barriers at an Ides of March costume party. With a harmless little reenactment of the Kennedy assassination as foreplay, the rest happened on its own.

Mrs. Pascal (an austere Geneviève Bujold) must have known what was going on, yet she is (understandably) reluctant to face the truth head-on. When Marty first decided to leave his sister to go to school, Jackie-O overreacted and sent him to the hospital with a bullet wound. Now, the twins have been apart for some time. Marty’s busy trying to reach a state of normalcy in college while Jackie-O skates along the brink of sanity at home. The slightest change may tip her over the edge. . .

Let’s just say that now is not a good time for Marty to present his new fiancée as a Thanksgiving dinner guest. Everyone’s apprehensive about who Marty will bring home, but we’re not talking Guess Who’s Coming to Dinner-style shocks. Lesly (Tori Spelling), Marty’s companion, is ordinary enough, but that’s the whole point. The real surprise awaits our innocent guest, who has no idea about the family she’s about to join. Lesly’s a waitress at the Donut King, and she’s just as eager as Marty to have a nice, normal marriage.

But Jackie-O wouldn’t hear of it. After all, the twins have a lot more in common than a few genes. “Jackie’s hand was holding Marty’s penis when they came out of the womb,” Mrs. Pascal fondly remembers. As if that weren’t proof enough that they belong together!

Perhaps the best advice would be for Lesly to split while she still has the chance. But you know how young lovers are. It’s easy enough to dismiss a few unusual remarks. If only she knew.

Sometimes we must ask ourselves, why translate a play into a movie? Is it merely to reach a wider audience, or does the film format make up for the limitations of the stage? All movies adapted from plays have the potential to attract audience members who might never have the chance to see the play performed on stage. However, only well-made adaptations manage to make the most of the transition, expanding the set or taking advantage of facial expressions to convey what only words could before.

Based on Wendy MacLeod’s play, The House of Yes is a film that still feels very much like a play. The characters in Yes don’t talk. Instead, they recite lines, lines that are sometimes so cumbersome no one would ever say them. Though natural enough to a distant theater audience, witty wordplay and crafty asides suddenly seem very awkward and oddly out of character when depicted in a closeup.

And yet, Parker Posey can handle them. She eats up the screen. While the film’s other actors often seem like phony cardboard stand-ins, Posey’s performance vibrates with an addictive devilishness. Something about the way she knits her brow or pouts her lips tells us that Jackie-O will always get her way. She’s downright rotten and a sympathetic character.

But it’s a problem that Posey outshines the other characters. Surely there are other actors who would have been better matched opposite her. If she can make her clever dialogue seem spontaneous, why can’t the others? Freddie Prinze Jr. as Anthony, the younger brother who is slow to catch on, is an exception, but his character doesn’t get as many good lines.

One of the blessings of comedy is that it allows us to laugh at the absurdity of normal things. The humor in The House of Yes is based on such unusual topics that the film is uncomfortable instead of funny. The laughs actually come from puns and Jackie-O’s clever, condescending quips. Yes is a movie that dared, but the effort doesn’t seem like it was worth it.