You are only guy in sorority. Okay, all girls there are taller and older than you, so they all are your seniors and superiors. So they looked down at you as on some child, using you to serve them and boss you around. You are sure, some of them even did not realize, you are a boy, not a girl, for them you were just someone younger and smaller to dominate and boss around. Girls see you less and less, until one day you realize, you became invisible for them. They do not see you anymore nor hear you, even if you stay right before their eyes.