Jim decided to mess with the girl further. “Control this girl’s submissiveness to me,” he whispered, then started blowing. There was no visible change to the girl. He figured he’d have to talk to her to see the effects. After adding several breaths to the balloon, he decided it would be enough. “Release, he said.
A bit nervous, Jim decided to go over to the girl to introduce himself. She was still looking confused, making discrete glances at her subtly enhanced bust. “Um, hi," he said. "My name’s Jim. I couldn't help but notice that you're kind of cute." She blushed, looking down at her feet. "T-thanks?"
"What’s your name?" he continued. “L-lizzie," she stammered. She trailed off uncertainly. Her eyes flickered back down to her chest again. “You seem a bit distracted. Is everything alright?”
Lizzie hesitated a moment before deciding that telling this boy the truth might not be such a bad idea. She sighed. "My chest is feeling a bit funny. I think I’ve outgrown my old bra. I was just heading to the lingerie section to find something more comfortable.”
Jim smiled mischievously. "Well, I would be happy to help you with that." She looked at him skeptically for a moment before slowly nodding her head. "Okay... thanks,” she replied, and they walked over together. “How about you go into the changing room, get undressed, and I’ll pick out some bras. I have a pretty good handle on chest sizes.” The girl gave him a questioning look, unconvinced, but the balloon had done its trick, and she did as he suggested, leaving for the changing room.
While Lizzie was gone, Jim quickly located the largest bra in the shop. There was no way she would fit in it, but that was no problem for the balloon. “Control how well Lizzie fits in any clothing she wears,” he whispered to the balloon. He blew as many breaths into the balloon as it would safely take, then said, “release,” and let the balloon deflate. Now any clothing she put on would change her body until she fit it perfectly. Jim made his way to the changing room.
He knocked on her door. “It’s Jim. Let me in?” he requested. After a pause, the door opened slowly. She was dressed in only her lingerie. Thanks to his change with the balloon, her breasts once again fit her old bra perfectly. “You know, now that I’ve gotten undressed and gotten a closer look, I think I was just being silly earlier. My bra seems to fit fine,” she said.
But Jim had something planned. He walked in, closing the door behind him. “You know, I went to all of the trouble to find the perfect bra for you. The least you could do is try it on.” Lizzie gazed at the bra, internally wondering if this was some kind of joke. The thing was massive, but her submissiveness to Jim got the better of her. "Fine," she sighed. "I'll try it." She took off her old bra and put on the new one. As she worked the clasp, Jim could see her chest slowly ballooning in size. By the time she had finished putting it on, the bra fit perfectly, like it was made for her.
"Wow," she gasped. "This fits great!" Her eyes widened as she realized what had happened. "Wait... but how did you..." She trailed off, looking more confused than ever. Jim smiled. "I told you. I’m really good at figuring out chest sizes.” She wanted to question him further, but her submissiveness kept her silent. Instead, she simply nodded her head, accepting his explanation.