High school bullying is a popular theme in movies. There’s one in particular that defines the genre. Before Mean Girls. Before Bring It On or Clueless, there was Heathers. This week, Heathers turned 25, and a Broadway musical based on the film opened. Like a high school loser who goes on to make a fortune in tech, Heathers was a flop when it opened in 1989. But it rose to cult status in the years since.