"Come on Joy," Sara said with a mischievous grin, "you can take a bit more."
Joy continued to expand, despite her attempts to remove the tube form her mouth. She felt like she was going to explode any second, but for some reason, she kept growing. Her breasts were now the size of Sara's entire body (inflated breasts included), her ass and belly inflated to equal sizes, her hips flared out as her legs thickened, and her arms began to inflate as well. The tank finally ran out of helium, leaving Joy wedged between the ceiling and the floor.
"Ooooh," Sara moaned as she rubbed Joy's over inflated breasts against hers.
"I'm...going...to...burst," Joy managed to gasp out.
"Well then," Sara said, "I guess we should..."