Ian McKellen agreed to play Magneto after Bryan Singer pitched him one sentence. "Mutants are like gays. They're cast out by society for no good reason." That pitch happened before the first movie shot a frame. Every gay allegory people found in these films afterward was put there on purpose, by people who had lived it. X2's most famous scene, where Bobby's mother asks "have you tried not being a mutant," came from Michael Dougherty and Dan Harris. Both screenwriters are gay men. They wrote a…