So many things about this picture are nearly impossible to believe: that its preposterous storyline is loosely based on actual events; that its writers are Andrew Jay Cohen and Brendan O'Brien, the team behind the two funny and inventive Neighbors features; and that it got likable and entertaining personalities Adam Devine ("Modern Family," "Workaholics"), Zac Ephron, Aubrey Plaza and Anna Kendrick together and somehow generated zero movie magic. 

Is it August already? That's usually the dumping-ground month for the summer's bottom-of-the-barrel big-screen fails. Yet here we are, barely into mid-July, and we're not laughing at a major studio comedy. Ninety-eight minutes has seldom seemed so long. 

The idea is that Mike (Devine) and Dave (Ephron) aren't just bros. They're really brothers, a couple of generically dim bulbs with a history of turning family celebrations into disasters. (Home movies of such events helpfully illuminate the audience in the movie's opening moments.) Dad — a squandered Stephen Root — plays the movies ostensibly to help his sons understand why he's laying down a new law as their sister's Hawaiian wedding date approaches. 

Thinking that it will keep them out of trouble, Dad instructs the boys to find proper, well-behaved dates to bring to the occasion. (In real life, the Stangle brothers' cousin was getting hitched himself, but the screenwriters here substitute their sister Jeanie for no apparent reason. Sugar Lyn Beard costars in this particularly thankless role. 

Mike and Dave decide to bypass dating services and advertise on Craigslist. The whole thing goes viral when more than 6,000 women respond. (The guys think they're the attraction, but it's really the free trip to Hawaii.) Naturally, this leads to them being interviewed on a number of TV shows. (The real Stangles also eventually wrote a book.) One of these appearances catches the attention — between bong hits — of best friends Alice (Kendrick) and Tatiana (Plaza). 

The movie's central, and really only, gag is that the girls are considerably wilder party animals than the guys. To win their two tickets to paradise, they get makeovers, fabricate respectable backstories and concoct a scheme to run into Mike and Dave outside a Manhattan bar. This involves Tatiana allowing a speeding cab to run into her. So, fairly early on, we perceive that this story is not in the hands of a Judd Apatow, Adam McKay or Paul Feig.

Rather, it's in the hands of first-time feature director Jake Szymanski, a 26-year-old who's made online shorts for Funny or Die. How lazy, repetitive and predictable is the film? Let's just say it would've died quickly had it debuted on that site instead of nearly 3,000 screens across the country last weekend. 

The cast is game, but there's only so much it can do with writing this limited. How many times are we supposed to watch Alice get hammered and still think it's a subversive hoot? I lost count of the dick jokes Tatiana made. But I know she kept making them right through to the outtakes. OK, we get it: Girls just wanna have fun. Just like the guys. Too bad the script didn't get another polish or three because, guess what, audiences do, too. What Mike and Dave really need aren't dates but better, more imaginative material.