"Since you've given me a penis, I'm gonna go first." said Karyn
"Seems fair" replied Jon. "Just start small, don't want to go overboard immediately."
"Lets add one more rule. You've got to close your eyes when its not your turn."
~~~~~~
Jon closed his eyes, and Karyn reached into the drawer.
She lifted out a vagina, and moved over to Jon. She pulled open the front of his boxers and pressed it up against his genitals.
Jon felt a warmth spread around his groin. Karyn saw the vagina become part of Jon's body, replacing his penis. But on closer inspection, she noticed she'd placed it on upside down!
"Okay Jon, It's your turn." Said Karyn, stepping back then closing her eyes.
Jon opened his eyes and immediately checked down his boxers. "Of course she'd do that" he thought. He took a close look at his new equipment, noticing something was odd about it.
"Wait, that doesn't look right... oh... She's put it on upside down..." he thought.
Jon knew exactly what he was going to change, reaching into the drawer he lifted out another flat chest, and pressed it up against Karyn's breasts.
The warmth spread across Karyn's chest, as the firm pecs became hers.