Zoe's New Anatomy

As Zoe swallowed the tic-tacs, she felt something wrong. He felt a terrible swelling sensation directly where her clit was. She dashed to the bathroom and shut the door, pulling down her skin-tight jeans and string panties to reveal a rapidly enlarging penis.
"YES!", she cried out as she stroked her still growing member. Her new dick respinded by getting immediately hard, and she stroked it again as it neared 18 inches. Her 13 year old body was surprisingly well developed, with nice wide hips and c-cup breasts, to top it all off, she had a very mature face that made her seem much older.
Her penis was growing a little more slowly now and she gasped as it reached a complete arm length from her head. She bent the tip toward her mouth and tentatively licked it. The intense feeling sent shivers up and down her spine, and she took the head into her mouth. She cried aloud at the amazing pleasure and when her other hand found her ass-hole, she came into her own mouth. She swalloed as much of the jizz as she could, but found a lot dribbling out onto her breasts. She was in a complete daze when she opened the door, her dick dragging and leaving a trail of spunk into the hall. She rounded the corner just in time to see Jon come racing back to retrieve the mints for fear someone might find them.
Jon shouted with surprise and nearly stepped on his sister's penis.