More than ten years ago I got a signed copy of of the Sandman hardcover graphic novels and attended a reading by him afterwards. At some point he asked if we wanted to hear two short stories or one long one, to which I shouted "two short ones AND a long one", and while he said that he couldn't do that, that's actually what he did. He sat there and read two short stories and a long one. Not sure if that's what a jerk would do.