"Let me make a few adjustments to myself first." Judy looked at the balloon.
"Judy, please," Jim said, but she paid him no attention. He was figuratively and literally beneath her now.
"Balloon," she said. "Control my boob size." She took a deep breath and blew into it. FFOOOOOOOFFFF. The two flesh balloons on her chest inflated with the red balloon in her hand. She blew into it again, FOOOFFF, and her breasts grew so large than Jim could barely see the top of her head beyond them. They seemed impossibly huge to him from his shrunken perspective. "Release," she said and let the balloon deflate. She cupped her massive tits again, hefting their weight. "Oh," she moaned. "They're so soft..." She squeezed them and tit flesh swelled out around her fingers. They were more than a handful now. "So... sensitive." She lifted one breast up and kissed it. "Oh yes, Mamma really likes."
Jim just watched in amazement, feeling his hard on stiffening even more under his hands. Now, he worried he might blow his load on her knees if he wasn't careful. He just hoped she was done now.
To his disappointment she held up the balloon again to make another change. "Control my leg length," she said. She inflated the balloon. FOOOFF. And, her already long legs stretched up higher like tree trunks in time lapse. "Release," she said. Jim realized he was now eye level to her crotch. He looked up at her face as she leaned forward to admire her incredible legs. She noticed him standing there with a bit of a start. She had all but forgotten he was still in the room. Then, she smiled at him. "Enjoying the view, little brother?" She asked him. She stood up straight, cocking a hip to the side and putting her hands behind her neck to push out her enormous chest. "What do you think of your sexy sister, Jimmy?"
"Judy," He said trying to reason with her as he tried to contain his own lust. "You need to turn us both back. What if Mom and Dad see us? You have to fix us."
"Hmm," she said letting her arms drop to her sides. Jim looked a the balloon in her fingers. It was now in reach if he lunged for it. He wondered if he had the strength to pry it from her fingers. He wondered if he could even inflate it at his size. "I suppose I could change Mom and Dad as well," Judy said. "Just imagine what I could do to them. I could make Mommy into a little toddler. She could wear my old dresses. Then, I would be the one in charge. She would have to do what I said, or else she'd be the one getting spanked for being a naughty girl. And, Daddy... I could shrink Daddy until he could fit in my old doll house. He would look so cute in my old doll clothes, and little Mommy would have a perfect toy to play with."
As Judy was lost in her imagination, Jim focused his attention on the balloon. He could grab it, but should he?