Big "Cusions"

Jon held up the die. All three looked and saw, the dice said Big Ass. Suddenly, they all felt as their skirts/pants and underwere/panties transformed into thongs. Before they could even begin to question this, they felt as their ass cheaks began to swell up. Soon they were so huge that they made cushions unnecessary. Finally they stopped growing. They realized why they were wearing thongs, there was no way anything else could fit. For some reason, Zoe didn't seem surprised. Instead, she just told them once agin to hurry up. As she left, Jon couldn't stop staring at his sister's giant ass bobbing around. Then he realized that he had dropped the die, and they were about to get a new change in top of the first.