Tit for tat

Jen picked up the stone. She wore a devilish smile.
"I wish..."
"Jen, don't!"
"That Karyn's boobs were a cup size bigger!" The stone flashed. Karyn looked down to see her naked D cups were now growing out. They stopped at double D. Karyn got out of bed and ran over to Jen, who giggled and tried to run. She chased her around the room, both naked, until Karyn caught Jen and got a finger on the stone.
"I wish Jen's boobs grew a little every time she got horny," said Karyn. There was a flash of light. Jen rolled away, letting Karyn have the stone.
"Bitch," she said, with a strange giggle. She looked down and saw her own boobs inflate just a little. They were almost as big as Karyn's now. "I'm gonna need a shopping card to carry them around if we don't put a limit on that wish."
"I wish Jen's boobs didn't grow bigger than an... I cup." The stone flashed again.
"Better?" she asked.
"So I'll only look like a porn star, and not a circus freak," said Jen. They giggled. Karyn felt herself getting hot. Jen's giggling and jiggling was getting to her.
"I've got one!" said Jen. Karyn tossed her the stone. Jen caught it, then smirked.
"I wish I knew what Karyn's fetishes were," she said. The stone flashed, and Jen found these images running through her mind. Now that Karyn was a lesbian, her fetishes had changed. She had a thing for feminine girls, loved skintight clothes stretched over nice curves, and had a little thing for bondage. Jen shuddered. Her breasts swelled a little.
"Isn't that a little private?" asked Karyn.
"I wish Karyn was wearing a skintight latex bodysuit."
Karyn gasped as the second-skin of shiny black latex appeared on her body. She looked down at her nipples poking through the latex. She peered down, saw she had a camel toe. She could feel the latex right up between her cheeks. It even covered her feet. Her hands and head were the only things not covered in the tight latex. She ran her hands over the material, feeling sexy, feeling trapped, but in a good way. She looked over at Jen.
"My turn," said Karyn. Jen tossed her the stone.
"I wish Jen was dressed in a tight corset, with garters, thigh-high stockings, six inch heels, and... and a big poofy petticoat."
Jen found herself standing ramrod straight as the corset appeared. She looked down to see white satin and lace cupping her generous boobs. Then she saw the poofy whiteness fluffing out from her waist. She took a step, teetering on the high heels. It felt weird, but at the same time, arousing. Her breasts pushed against the satin, growing to an E cup. She walked towards Karyn, who looked down at her own clothes.
"Wanna give me some sexy footwear?" she asked with a wink. Jen took the stone.
"I wish Karyn's breasts got bigger when she got horny, but never bigger than an I cup."
The stone flashed, and Karyn grabbed the stone back.
"I wish Jen's petticoat got poofier the more... The more I got turned on."
Karyn's breasts swelled out to an E cup just as Jen's reached double E. Jen's petticoat stood out at a full forty-five degree angle. The two girls smirked at each other.
"This is twisted," said Jen.
"I love it," said Karyn. She tossed the stone away and grabbed Jen, pulling her into a deep kiss. They felt their breasts swelling into each other, which just turned them both on even more. When they broke the kiss, both girls panting, their breasts were almost solid F cups. Jen's petticoat had gained more poof and threatened to stick out more than her huge breasts.
Jen dragged Karyn over to the bed.