By all appearances, new parents Mac (Seth Rogen) and Kelly Radner (Rose Byrne) are living the American Dream, one complete with an adorable little girl and a beautiful new starter home in the suburbs. Still, the early-thirtysomethings want to believe that they have a modicum of coolness left within them. This next phase of life is proving to be a challenge, as the reformed (sometime?) partyers struggle with the realities of entering an inevitable new stage: unapologetic adulthood.

When Mac and Kelly discover that their new nextdoor neighbors are none other than dozens of Delta Psi Beta fraternity brothers—led by charismatic president Teddy Sanders (Zac Efron)—they try to play along and make the best of an awkward situation. But when the frat’s parties grow increasingly more epic, both sides of the property line begin to fend for their turf.