After having his girlfriend Tracy break up with him, Erik Stifler and his friend Mike “Cooze” Coozeman arrive at the University of Michigan as freshmen. Upon arriving at his dorm, Erik meets a girl named Ashley while she is taking a shower in the coed bathrooms. He then meets his new roommate Bobby and his girlfriend Margie while they are having sex. Erik is then welcomed by his cousin, Dwight Stifler, the leader of the Beta House fraternity, who invites Erik, Cooze, and Bobby to a Beta House party. They meet Wesley, the rush chair of the Beta House who experiences blackouts after drinking alcohol, and learn how they can gain eligibility to pledge for the Beta House. They are also informed by Dwight that the Geek House, formed by wealthy nerds, has been trying to shut down Beta House.
Erik and Ashley begin dating, but on their first date at a restaurant, Erik is accidentally spilled hot soup on his legs, so Ashley brings him to her room to clean up. As Ashley rubs lotion on Erik’s thigh, he involuntarily develops an erection and accidentally ejaculates over her possessions. Erik apologizes and explains to Ashley that, after breaking up with Tracy, he has not ejaculated in four months, masturbation being a taboo on his house because of a previous incident. Meanwhile, Cooze falls in love with Ashley’s roommate Denise; however, she is nervous to show him her genitalia and have sex with him, so she instead gives Cooze a handjob. After talking with Erik, Bobby, and Dwight about Denise, Cooze develops suspicions that Denise might have a penis, so Dwight encourages Cooze to find out.