Mary surveyed their situation. They were both catgirls, a mere 4'6" each. "Well, I kind of miss being tall," Mary thought out loud.
"Yeah," Jess agreed. She continued looking through the vial box until she noticed ones marked "Shrink" and "Growth." She showed them to Mary.
"All right," Mary smiled. She was about to take the vial from Jess when Jess pulled it away.
"Wait a minute. What if this thing can grow us even larger?"
"What are you thinking about?" Mary wondered.
"I'm thinking we can have ourselves a really fun time on the town...if we just expanded our possibilities."
"Nice pun."
"Thanks." Jess didn't wait for Mary's approval before she guzzled down the entire vial. She capped it, watched it refill, then handed it to Mary.
"I'm not sure about this," Mary hesitated.
"Oh just hurry up. I don't want to be the only one doing this."
With a shrug, Mary gulped the refilled vial and put it back in the box. Jess had already started her expansion, back to her original height and quickly surpassing it.
"We'd better get out of the house, Jess," Mary thought suddenly. "Quick!"
Jess ducked out Mary's bedroom door and quickly ran down the steps. Now she had to duck just to keep from hitting her head on the ceiling. She opened the front door and crawled on all fours outside. Mary followed behind her. Their shirts began to rip apart from the strain of their growing chests, and with their claws, the catgirls tore them off completely.
Jess stood up and saw she was at eye level with Mary's two-story house. Mary was just a few feet under her height, but they were both growing at the same rate. She could feel the air growing colder as she ascended.
"Isn't this great?" she asked Mary, rubbing her fur as they shot higher and higher. They were at least forty feet tall and still climbing. Jess began bounding down the street toward the nearest mass of skyscrapers. "Look out, world! The giant catgirls are coming!"