Amanda sits back and watches as the very well endowed Maddi and the six year old Liz start running. However, Maddi, despite having bigger breasts does have a height advantage, and thus runs farther than Liz, who's legs were very short.
Maddi crosses the finish line first and finds her pussy talking to her as her breasts get a size smaller. "AW, dammit." you say. though you are no longer Amanda's pussy, you are now Maddi's.