Both wishes were granted, but since they were spoken at the same time, the result was that they got mixed into one wish:
"I wish I was content with my red-dyed hair and breasts."
The stone flashed and Jon looked at Karyn, shocked. "What happened?!"
The mixed wish was granted to both of them. Karyn's hair had been dyed red and she was perfectly content with her DD sized breasts.
But, apparently so was Jon. He looked in a mirror at himself. His hair was dyed red, also. And he had breasts! Not as big as Karyn's, but big enough to be noticeable.
