Human sexuality is a complicated thing. But despite decades of research into fluidity and the Kinsey scale and the fact that not even gender is as binary as we'd like to think, some fans expect characters to fall into one of two categories: Straight or Gay. When one Shipper too many writes that a canon flirt has lost all interest in women after getting into a slash OTP, or insists that same-sex pairings are automatically out-of-character for someone who has only ever given the opposite sex the eye, you may feel the urge to shout Bisexuality Exists Hotdamnit!