Ms. Caster heard the muttered complaint.
"I suppose bigger is better, would be your perspective." Jonathan looked over, a icy dread running down her spine.
"Let's see..." She mused, as Jonathan squirmed in her seat. Desperately she wanted to flee the room, but some force was keeping her seated.
"What kind of young woman do you fancy?" Her words reaching the transformed student's ears. "That is... what kind of young woman do you fancy,... being, Jenny."
In that moment, Jonathan's bag shifted from the sturdy bag filled with his sports gear, and books for that day. In it's place a pink bag appeared, covered in inky scribbles, and holding Jenny's cheerleading outfit. The mini-skirt, and mid-riff baring top fitted easily inside, while her pom poms were stuffed into the pockets on the outside of the bag. Proudly announcing her position on the cheer squad.
"Hmmmh, I'm not really surprised." Myrrine mused. "But, you did think you needed to be... bigger."
Her hands cupped in front her own chest miming a bust swelling larger.
"Jenny..." she called out, "I hope Jonathan had some restraint, or you're going to be a very big girl."
Still squirming, she shook her head, in denial... That stopped as her eyes widened in horror. She felt her bust develop. Leaving the subtle B-cup behind, the girls mooshed by the too-small cups, looked even riper, as they spilled over the cups.
As the pain intensified, Jenny reached to adjust herself. In that moment, the frilly cupped bra, shifted too. Developing bigger cups, broader straps, and a generally sturdier appearance.
She whimpered, as she saw, her new bigger bust seemed dwarved by the new bra she was wearing... It wouldn't be so bad, if it weren't so ugly and plain.
Jenny caught that thought, and shuddered. She knew she was battling against losing herself. Against losing to Johnny's idea of what kind of young woman he wanted. Mortified, she snatched her blouse shut.
- - - - -
Well, as best she could, the buttons no longer meeting in the middle over her expanded and still expanding bust.
"I think you're a D-cup girl." Ms. Caster mused, receiving a glare from Jenny.
She shrugged it off, "Don't blame me, this is your fantasy Johnny-no-more."
A distracted look passed over Myrrine's face. "Oh... you'll like the next part. I never knew Jonathan was such an afficianado of womens' asses."
There was a crack from Jenny's hips, and her hands dropped from clutching her blouse closed. Jenny's pelvis widened, giving her a fuller ass. Johnny didn't want a flabby ass, so Jenny was impossibly firm and impossibly full. Her perfect round ass an open invitation to watch.
Her hands flapped like a headless chicken's wings, as she tried to push them back. Force them into the more familiar male shape. But, it was long gone, and her fingers sank into the supple flesh of her thicc thighs.
"Apparently, you're not proud enough of your achievements, Jenny." Myrrine seemed to be reading the magic, or Johnny's mind seeing which direction it was heading.
- - - - -
Jenny's blouse and pants vanished, leaving her just in her underwear for the briefest moment. Between one breath and the next, her cheer uniform vanished from her bag, to being worn. The too short skirt, felt her hands trying to tug it lower. Her swelling bust, filling out the top, and distorting the school's logo.
"I don't imagine you should be so athletic..." Myrrine observed. "They'll be heavy, and your shoulders will hurt."
As her attention returned to her bust, Jenny saw she was even bigger. The outline of her bra visible even through her cheer sweater. "An E-cup.... No,.. I think you're an F-cup girl." Ms. Caster told her.
Jenny's hand's tried to squeeze them, force the back flat, or at least flatter. But, the gasp that burst from her lips was telling, sounding far more sensual than any sound she'd heard before.
"Oh, you're more sensitive too. Johnny didn't want a young woman who couldn't enjoy herself..."
Jenny blushed beetroot, and snatched her hands away from mauling her bust. Silently apologising for every crude tweaking, teasing exploration he'd done while still unaware how it all felt as a young woman.