Steven "Steve" Stifler, usually referred to by his last name only and he also addresses himself as the "Stifmeister", went to East Great Falls High. It is unknown how good he was academically (although he says in American Wedding that he was "always more of a 'C' student" to Cadence), but he was on the school Lacrosse team.
While not part of the sex pact, Stifler plays a crucial role in the film in two ways: his post-prom party (an invitation to which was the motivating factor for the main four characters to even associate with Stifler) served as the setting for the film's final act.
Stifler also becomes obsessed with ruining one of the main characters (Finch) by exposing him as a geek to the girls of the school after Finch arranges for rumors (including one where he had defeated Stifler in a fight) about himself to be spread across the school in order to make him desirable as a prom date, resulting in Stifler's planned date dumping him in hopes of getting asked out by Finch. Stifler's revenge culminated in him putting Pentalax, a potent laxative, into Finch's drink of choice (mochaccino), giving him a case of explosive diarrhea that results in Finch being humiliated in front of a large group of female classmates. Finch however got revenge by making one of the rumors accurate, which was stiffing Stifler's mother.
Stifler is also on the wrong end of the first of three sight gags throughout the film's trilogy in this movie. After Kevin ejaculates into a full plastic cup of beer on a nightstand in a bedroom while trying to lose his virginity, the cup is replaced on the nightstand and Kevin and his date leave. Stifler comes in a short time later and as he's seducing his date, picks up the tainted beer and takes a large gulp, resulting in him making a mad rush to the toilet and vomit. Kevin asks him how the pale ale was, and Stifler shouts "Fuck you!" in disgust.
Stifler was also responsible for convincing Jim to set up a live Internet broadcast, when the sexy foreign exchange student Nadia arranges to get changed in his bedroom, only to ultimately begin masturbating to his collection of Porn magazines. The broadcast was witnessed by Finch, Kevin, Steve, his little brother Matt ( who describes it as "the coolest thing he has ever seen"!) as well as the entire high school directory, after Jim addressed the email wrong.
2000: Beach House VacationEditStifler reappeared in American Pie 2, having boasted of bedding 23 separate girls during his freshman year of college, not including the hummer he "got in the library stacks." He went to Michigan State University. Along with the main clique of the film series, Stifler helps chip in cash to rent a beach house on Lake Michigan with the rest of the group.
In this movie Stifler gets urinated on while under the impression that a girl is pouring champagne on him. Stifler is sitting on a lawn chair with his back to the house as John is urinating off the second-floor balcony and into Stifler's open mouth. He later comes back into the house and says morosely "I got peed on."
During the summer, Stifler becomes obsessed with the owners of the house that they were hired to paint; two female friends who Stifler optimistically regards as lesbians, who deal with Stifler's obsession ultimately by offering to engage in varying degrees of lesbian sexual activities in front of him, Jim and Finch but only in exchange for the guys to engage in a corresponding degree of homoerotic acts that girls enjoy. The first is Stifler grabbing Finch's buttocks, the second is Stifler and Jim kissing, and the third one would have been for Stifler to receive hand jobs from Finch and Jim, which Stifler is surprisingly willing to do. This freaks Jim and Finch out too much and they run off. This annoys Stifler, as the more the guys would have done, the more the girls would have done. At the main party at the beach house at the end of the film, the two girls arrive after speaking with Matt over the walkie talkies, telling Stifler they never said they were lesbians, that gets Stifler far more excited and ends up in bed with them both.
2003: Jim and Michelle's WeddingEdit
In American Wedding, Stifler is the story's main protagonist. He is revealed to have become a high school football assistant coach; he also drives the team's bus. He drops in on Jim and Michelle's engagement party, much to Michelle's dismay. He is also implicated in an unusual Jim-plus-two-dogs foursome (which Stifler admitted to enjoying). He later competes with Finch for the heart of Cadence, Michelle's younger sister. He impersonates Finch's personality of an upper-class, educated gentleman in order to win Cadence over, but Finch continues the triangle by replicating Stifler's vulgar frat boy image, which Cadence surprisingly enjoys just as much, if not more.
Nevertheless, Stifler manages to bond with Cadence's family, and is eventually charged with holding Michelle's wedding ring. However, the dog manages to ingest the ring while in Stifler's care, and Stifler follows it until it defecates. Steven picks up the ring (encapsulated within the feces) using a confection paper, which Cadence's mother sees and assumes it to be one of the truffles. She insists that Stifler let her have it, but knowing he could blow his chances with Cadence for good, he suddenly pops the dog dropping into his own mouth.
Before the wedding, Stifler accidentally destroys the massive flower arrangement Michelle's family had ordered, resulting in Michelle and Cadence turning against him. However, Stifler redeems himself at the end of the film: using the football team as his minions, Stifler uses his own money to buy up the entire content of a nearby flower shop and has the football team successfully set up the flowers for the wedding hours before it is to occur. By doing this, Cadence eventually falls for him and invites him to have sex in the closet. Stifler accidentally has sex with Jim's grandmother, who was put in there because she was "being a bitch". At the reception, Stifler danced with Cadence, and congratulated his friend Jim for successfully pulling off the wedding, by telling him "You did it!"
2005 - 2009: Later LifeEdit
By the time of his brothers stay at Band Camp, Steve and Cadence's relationship appeared to have ended and he has become an amateur soft core porn director. His only contact with his younger brother is through letters and postcards from various places he had been 'filming'. It is unlikely any of his films were legitimate, due to the revelation of his real workplace in American Reunion, and possibly the job was made-up to either impress his friends or bed women. In Naked Mile, it is revealed he at some point sent a picture of his exposed buttocks to his cousin, Erik. A picture of him can be seen on Erik's noticeboard. It is apparent that Steve still kept in contact with his family members including Matt, Dwight and Erik.
2012: East Great Falls ReunionEdit
Stifler is the story's deuteragonist. He is re-introduced seen working at an office but wants to party as usual. He is still childish and immature and he plans on partying with his friends, but it backfires when they drift apart from him and Jim, Kevin, Oz and Finch later apologize to him at work. He quits his job after his boss is being a jerk to him and this shows that he has sort of matured but is still childish.
When Ron threatened to sue Oz for all he's worth if he punched him, Stifler punches Ron exclaiming "I ain't worth jack shit!" When Finch's mom appears at the reunion, Stifler decides to sleep with her as revenge from all the times Finch has had sex with his mother. He has sex with her at the high school's soccer field, with the two MILF guys chanting MILF.
At the end, Stifler joins the rest of the group for lunch at Dog Years and they all agree to meet up with each other at least once a year to catch up. As this goes on, Stifler makes subtle hints about sleeping with Rachel (Finch's mom), but no one picks up on it (with the possible exception of Finch as he is the first one to respond and his response sounded as if he was in shock).
- Despite his family members appearing in almost every film, Steve only shares onscreen time with Matt. He is never onscreen with his mother, either; in the first film, Stifler sees his mom and Finch having offscreen sex on the pool table, and in American Reunion, he talks to his mom on the phone, but in separate shots.