Three ex-girlfriends of a serial cheater set up their former lover to fall for the new girl in town so they can watch him get his heart broken. Kate (Brittany Snow) is the new girl in school. She catches John Tucker (Jesse Metcalfe) dating three different girls at once: Carrie - the smart girl, Heather - the cheerleader, and Beth - the activist slut; none of them are aware that they are not the only girl in John's heart. Kate, having been raised by a single mother, has seen the pain caused by playboys like John Tucker, and she won't stand idly by. Together with the three jilted ex-girlfriends, they hatch a plan to teach John a lesson. Things rarely go as planned, especially when Kate starts to think that she might be falling for John herself.