Jon has the body of a centaur, but has a male human half and a female horse half.
Jon looked down at himself. He knew that his memories were probably altered by the pencil, but it was so odd to think of himself as anything other than the centaur he had always been.
"So, I wasn't always a centaur?" asked Jon.
"How many centaurs are there in society?" asked Karyn.
"I don't know," said Jon. "A lot. Or did the pencil change that too? Is everyone human like you?"
The wish must have changed other people to centaurs to accomodate Jon's change, thought Karyn. That would explain why Jon didn't see anything strange about his body. If centaurs were normal, they wouldn't see themselves as strange at all.
"And what do you mean 'female horse half,'" asked Jon. "I have a male half."
"But you have a uterus and vagina, Jon," said Karyn. "Those are female organs."
"In humans yes," said Jon. "In centaurs, males have the babies, thus my uterus and vagina are male organs, not female. If I really had a female half, I would have a penis."
"The wish must have taken it from the human perspective," said Karyn. "From my perspective, you have a male human half and a female horse half. From your perspective, since sexual organs are the reverse of humans, you are totally male."
"So what," asked Jon. "I'm supposed to be human. Do we change it back right away? Or do we do it later?"
"How about later," asked Karyn. "I want to see how things have changed, if that's all right with you."
