Steven "Steve" Stifler, usually known as simply Stifler, made his first appearance in American Pie, in which he went to East Great Falls High. While not part of the sex pact, Stifler plays a crucial role in the film in two ways: His post-prom party served as the setting for the film's final act. He is also a close friend of the guys, especially fellow lacrosse player Chris "Oz" Ostreicher and Jim Levenstein. Despite his love-hate friendship with Paul Finch, it is apparent that they are still good friends. After Finch pays to have positive rumors about himself spread to all the girls in the school, one of these being that he won in a fist fight with Stifler, Stifler reveals Finch as a freak in front of everyone by putting very strong laxative in Finch's habitual drink of mocha cappuccino. Finch, who is too uptight to use the school toilet until that time, ran to the restroom, where Stifler helpfully held the door open for him. It turned out to be the ladies' restroom, and Finch was publicly embarrassed. Stifler is also on the wrong end of the first of three sight gags throughout the film's trilogy in this movie, where he ingests beer containing semen. He then proceeds to vomit uncontrollably on a girl and in the toilet.[2]
Stifler's second appearance was in the sequel, American Pie 2 (2001), with a much larger role this time. After returning from his first year at Michigan State University with Oz, Stifler helps chip in cash to rent a beach house on Lake Michigan with the rest of the group. During the summer, Stifler becomes interested in two attractive owners of the house that they were hired to paint; two females who Stifler mistakenly regards as lesbians, who respond to Stifler's attraction 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 or Jim, which Stifler is the only one confident enough 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, telling Stifler they never said they were lesbians, and Stifler ends up in bed with them both.[3]
In American Wedding, Stifler is the 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 their dismay. He is also implicated in an unusual Jim-plus-two-dogs foursome. He competes with Finch for the heart of Cadence, Michelle's younger sister. He impersonates Finch's personality in order to win Cadence over, but Finch continues the triangle by replicating Stifler's outrageous 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 family dog manages to ingest the ring while in Stifler's care, and Stifler follows it until it defecates. Stifler picks up the ring which is 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 devours the dog dropping into his own mouth. Before the wedding, Stifler accidentally destroys the massive flower arrangement Michelle's family had ordered, resulting in everyone turning against him. Jim tells him to leave, and seeing how no one is on his side, Stifler complies. 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 there by John and Justin because she was "being a bitch". At the reception, Stifler dances with Cadence and congratulates his friend, Jim.
In Band Camp, the audience are told that Stifler has become a pornographic movie director. This movie shows that although the jocks and other popular kids pretended to like Stifler he was not liked by anyone in high school. In American Pie Presents: Naked Mile, he is mentioned in passing by his cousin Erik as one of the legendary Stifler boys. A picture of him can be seen on Erik's noticeboard.
In American Reunion, he is portrayed in a slightly lighter fashion and can be considered somewhat of a tragic character. He now works as a temp at an investment firm, having to put up with the cruel verbal abuse from his arrogant employer. He yearns for the days of his youth and has trouble coping with the fact that things will never be the way they were before. Throughout the film, he attempts to re-create his teenage years (such as seeking revenge on a group of antagonistic teens and throwing one of his trademark parties) but fails each time as his friends and everyone else has outgrown this. When Stifler learns Finch was arrested for stealing his boss' motorcycle, he finds it hilarious thinking he got his revenge on Finch because he slept with his mother the previous times. Meanwhile Jim, Oz and Kevin are offended with Stifler's lack of sensitivity towards their friend and rallies to Finch's side. During a heated confrontation with the guys, they reveal they don't like having Stiffer around because he acts like an immature prick and always ruins their plans. Stifler is heartbroken and decides to skip the reunion. However, the guys soon realize how much they mean to Stifler, and how much he means to them so they locate him at work and make amends with him. He regains his confidence and quits his job (but not before telling off his boss). The guys proceed to attend the reunion, finally embracing Stifler as one of their own. Stifler catches up with Chuck "Sherminator" Sherman, and feeling bad for how he treated him in high school, Stifler wholeheartedly helps Sherman find a woman to score with. In a surprise turn of events, he meets Finch's gorgeous mother and finally has his revenge by having sex with her on the lacrosse field as the MILF Guys, John and Justin, happily watch. In the end, the five friends all promise to stay in touch and meet up at least once a week from now on to catch up.