Karyn had made plans to stop by Jon's house before they went together to the mall. And about half an hour after Jon arrived back at home, Karyn called him and said that she was on her way there. It would only take her a few minutes.
Jon used this opportunity to use the stone. He had always had feelings for Karyn, even if it wasn't totally noticable. He saw this as his chance to get what he always wanted: a relationship with Karyn.
Believing that Karyn would be the next person that he'd see, Jon said "I wish that I and the person I see next would want to have sex together and have a sexual love relationship with each other and wouldn't care if other people knew about it."
Smiling, Jon waited for Karyn to show up. A few minutes later, he heard the doorbell ring. That's her, Jon thought, in anticipation.
There was a knock at his door. He opened it.
