The doorbell rang, it was David's friends Tom and Carl. They'd come over to see what David had bought at the magic store earlier. David's head was still reeling from the revelation that he could change the world however he'd like. He let them in, and the three of them went into the kitchen. Tom, Carl, and David had known each other for years, they were best friends. David put some pizza rolls in the microwave and asked, "If you guys got one wish to change anything you'd like about yourself, what would you change?" he asked casually. Carl looked at him quizzically, "uhh, weird question, but I guess I'd make myself smarter, so that school was a breeze." David and Carl looked at Tom who had a grin on his face, "I'd give myself a huge dick" he laughed. The pizza rolls finished up and they guys started eating them. David excused himself to go to the bathroom. He rubbed the ring a little and thought, "I wish Carl was a genius" the ring glowed for a moment and then stopped, David figured it had worked. He moved on to Tom, "I wish Tom had a 16" penis" The ring did its thing, and David rejoined his friends in the kitchen.
David stepped into the kitchen, Tom was standing there with his pants down and his new and improved penis hanging down. He and Carl were staring at it. They looked at David, Carl spoke first, "You made a wish, David left, and your wish came true, it stands to reason that David has the ability to grant wishes."