most schools learn in seventh grade. Like every other male in the Twilight series (excluding Charlie and Billy Black, whose interests lie elsewhere), he wants Bella's jailbait booty, because if there was a single character who didn't she wouldn't be speshul enough. That's not totally sick and wrong. There's nothing wrong with pedophilia (if you live in Meyerland that is).
This man, just for finding Bella attractive, has forever sullied the name of Banner and shamed The Hulk.
Mr Banner also took part in Twilight's war against feminism saying, when he walked around the class to look at how the students were doing with their work, that Edward must stop doing all the work for Bella. He, somehow, couldn't believe that Bella had done half of the work, because she is a woman and therefore can't possibly know anything about science.In Midnight Sun, Edward claimed that Mr. Banner has a thing for Bella since he can read his mind, making Banner one of the men who chases after Bella (the counter is on 6, just fyi). This is disturbing for obvious reasons. So this is what Meyer chooses to portay over sex..
Mr. Banner may have been based on Stephenie Meyer's teacher (which again makes us feel uncomfortable), or maybe Hulk himself.