With high school a distant memory, Jim and Michelle are getting married — and in a hurry, since Jim's grandmother is sick and wants to see him walk down the aisle — prompting Stifler to throw the ultimate bachelor party. And Jim's dad is reliable as ever, doling out advice no one wants to hear.

Everyone has 'moved on', except for Sherman and Jim Levenstein's still understanding father. Little Matt Stiffler wants to join his older brother Steve's business and, after everything Matt has heard from Jim's band-geek wife, he plans to go back to band camp and make a video of his own.

When Erik Stifler realizes that he's the only Stifler family member who might graduate high school a virgin, he decides to live up to his legacy. After some well-meaning advice from Jim's dad, Erik's ready to take his chances at the annual and infamous Naked Mile race, where his devoted friends and some uninhibited sorority girls will create the most outrageous weekend ever.