A girl comes over.

Jon's family was out that night. He hear a knock at the door, he went down to see who it was. When he opened the door he saw a young woman, pure black hair, somewhere in her 20s, about the same height as him, wearing a long black dress.
"Hello. Are you Jon?" She asked.
"Yes."
"So is it true, that you have the ability to get any girl pregnant?"
"Yes, are you-" He stops not knowing the girls name, when her name then appears in his head. "Amanda."
"Yes. That's me. May I enter." Jon lets her in.
After a few questions, and a not so detailed explaination of how the ring worked. Jon learned that she is only 23, and has the inability to become impregnanted. His biggest thought was why she was so eager to get pregnant, but he didn't question it.
"Ok. Lets get this over with." Amanda said as she began to strip off all her clothes. Not fully understanding Jon stripped as well. Amanda seemed to take this in no way sexually as she simply pushed Jon onto the couch and inserted himself inside of her. Jon was a virgin, and her movements had him building up quickly. He realized that the words he told her were that he had a ring that can get a girl pregnant if his semen touched her. Obviously she must have understood that as if he came inside her like any other person would. He would have to try again, he can't be sure that the stone didn't just make her think she was unable to conceive- Jon's train of thought was cut off as he felt his dick shooting out into Amanda's pussy.
Right afterwards Amanda gets up, gets dressed, says "Thanks", and leaves.