The newest collaboration of former "Saturday Night Live" BFFs Amy Poehler and Tina Fey proves that smart people cannot always escape cliche.  "Sisters" has an implausible, though energetic concept for the comedy-hungry forty-something crowd.  It co-stars a bevvy of funny favorites like Ike Barinholtz, Maya Rudolph, John Leguizamo, John Cena, and Bobby Moynihan.  Unfortunately, "Sisters" has no ability to buck predictable formula.  Even a go-for-broke, R-rated potty-mouthed jolt from two of our favorite, and normally buttoned-up, comediennes can't save this film.

Amy Poehler plays Maura Ellis, a completely square rule-follower nurse who always thinks the best of people and worries about everything under the sun.  That chipperness is balanced by a complete lack of sexual courage as a failed divorcee.  Her sister Kate (Fey) is the polar opposite, a partying screw-up who cannot hold down a job or properly support her teenage daughter (Madison Davenport of "Noah").  As different as Maura and Kate are, they are inseparable (naturally).  

Maura and Kate are rocked by the news that their retired parents, Bucky and Deana (James Brolin and Dianne Wiest, coincidentally still playing spouses on CBS's new show "Life in Pieces") have sold their beloved childhood Orlando home to a pair of yuppy newlyweds, Mr. and Mrs. Gertt (Santino Fontana and Britt Lower).  Both have been asked to come back home and clean out their old rooms.  Making the trip to Florida together, the sisters reminisce about their embarrassing 80's fads, different life paths, and memorable "Ellis Island" parties.

For one last hurrah and a fleeting hope of sticking it to the Gertts, Kate sells Maura on the idea of throwing one last rager and reunion party at the Ellis homestead.  They hit up (almost) all of their old local high school classmates to attend, and Kate helps Maura confidently woo a newly single guy down the block (Barinholtz) to make it an eventful evening.  Once the booze starts flowing, the lesbian DJ starts spinning tunes, the hot Korean nail salon girls show up, and the wrongly-introduced casual drugs kick in, these children of the 70's and 80's tear it up like old times.

Alongside the debauchery and dancing, "Sisters" weaves in some hurdles for Kate and Maura.  Even back home, Kate is now homeless and unemployed.  She sees potential financial help in the form of her parents sharing the sale of their home with her.  As for Maura, she's keeping something from Kate while needing her sister's confidence to rub off on her in order to calm her worries.  There's nothing colossal going on, so expect a tidy climax.

Therein lies the biggest problem with "Sisters."  Tidiness takes away any edge.  It markets itself with a rebel yell, yet contains no veritable courage to push any envelopes or take any risks.  Profanity isn't enough to buoy flat jokes and skit-like breaks in the narrative.  No one from the assembled mass of comedic talent can reach higher than the low hanging fruit.  By the time Florida sinkholes and accidental anal insertions show up, you've rolled your eyes enough and checked out.  

If you've seen one "bonding sisters" or sibling relationship movie, you've seen them all.  Even last year's so-called brilliant "Trainwreck" falls for these formulaic trappings.   The predictability of "Sisters" in that way is its last straw.  You will see the usual course: a temporary argument, a impetuous sibling break-up, an awkward eventual (and required) make-up, and just enough time left over for lessons to be learned, apologies to be said, and everything to be made right with hugs.  Fey and Poehler are smarter and bolder than that, but it doesn't show.

LESSON #1: DON'T KEEP SECRETS FROM YOUR CLOSEST FAMILY MEMBERS-- Secrets among family members never work.  They rarely protect anyone.  They'll almost always create unnecessary hostility.  Be honest and up front with family.  It should be easy.

LESSON #2: BIG PARTIES AT HOME ARE NEVER A GOOD IDEA-- Throw a big party somewhere else other than your own house.  The massive clean-up, extra out-of-pocket costs, and the potential property damage aren't worth the trouble.  You're all 40-plus.  Go to the casino, the horse track, or Dave and Buster's.  

LESSON #3: YOU'RE NEVER TOO OLD TO PARTY, BUT ACT YOUR AGE-- Everyone is allowed to tap into the youthful spirit to drink, frolic, and have fun.  However, act your age.  Leave the old high school grudges at home.  Tone down the recreational drugs and know your alcohol tolerance.  Lastly, remember life's mature responsibilities that will be right around the corner after your hangover wears off