Swimfan (2002)

Ben Cronin is a high school senior who has just about everything going for him. He has a great girlfriend, Amy, and a swimming scholarship to Stanford in the works. Ben's life seems almost perfect. Then Madison, the alluring new girl in town, develops a crush on Ben, although she says she just wants to be friends. But it seems that Madison has an odd way of defining "friends." As Madison's obsession with Ben grows, his life begins to unravel. First, he is kicked off the swim team for using steroids that he swears he's never taken. Then, his best friend runs into troubled times and all clues lead to Ben. Finally, Ben is accused of endangering Amy's life and putting her in the hospital. Ben suspects that Madison is behind all of it. With no one on his side, Ben dives into investigating her past and finds some incredibly dark secrets. Convinced that Madison will do anything to ruin his life as well as the lives of those around him, Ben decides to set the record straight.