Nothing happens. You keep rubbing the ring, but there is no glow, nothing. The Master looks down and notices the ring stuck to his cock. "What the hell is this?" He grabs it, and sees the ring on your finger. He grabs it as well. "So, is this some sort of spell you are trying to work on me?"
"No Master," you say quickly. "This is the gift I was offering you, but you didn't believe me."
"I doubt that," he said. He takes both rings to the bathroom and flushes them down the toilet. Your heart sinks as you realize that you must spend the rest of your life as a slave girl to this harsh Master with a huge cock. But suddenly you realize how much you enjoyed being fucked as a girl by such a huge cock. Your Master returns and grabs you by the hair. "Now you take it in the mouth,' he says, and you open wide.
His dick springs up and he sticks it deep in your mouth. You suck it and rub it with your tongue. He slides it back and forth, still holding you by the hair. You suck it, and finally it spurts out hot cum, which fills your mouth and spills out and runs down your chin. It tastes salty, and you realize it tastes good. You are enjoying it.
Then your Master pulls it out, and it's still rock hard. "Did it taste good?"
"Yes, Master, it tastes so good," you hear yourself say. "Fuck me some more with that enormous cock!"
He smiles and sticks his cock into your pussy. It slides in more easily this time and doesn't hurt at all. In fact it feels so incredibly good. You say "Fuck yes! Fuck me, Master! I want it so bad!"
"Are you my slave girl?" he asks, fucking you hard.
"Fuck yes, Master," you say. You love being a girl, and you love cock so much. You know you are where you belong, and you are content to be a female sex slave forever. Your journey ends here.