"She's so proud of those boobs" Cheryl said, "Let's see how she likes them now"
She hit a series of buttons and until the remote described the desired transformation on its tiny LCD screen:
FEMALE BUST INCREASE: +3 CUP SIZES
Satisfied, Cheryl discretely aimed the remote at Tiffany and pressed the PLAY button. She saw a faint, nearly invisible beam launch straight forward from the device and struck her sister harmlessly.
All of a sudden Tiffany's chest began to get bigger. Tiffany looked down in shock as her boobs got to big for her bra, and it snapped off. After a minute or so, there stood Tiffany but with size E or so boobs.
"Wow, that's incredible," said Cheryl as she watched her sister checked out her expanded chest, oblivious of her sister's actions.
A moment later, Cheryl realized that her sister was actually pleased with her sudden growth spurt from C-cup to E-cup.
"Dammit, she's supposed to be upset! I can't believe I just made her happier!"
Cheryl's hand clutched the remote angrily and muttered, "well let's see how Tiff likes them after this!"
She aimed for her sister and stabbed the PLAY button again.
Tiffany was amazed to find her boobs growing rapidly for the second time in five minutes. Shortly a pair of huge H-cup tits were stretching her tight-fitting T-shirt to its limits, with enlarged nipples visibly tenting against the taut fabric.
Cheryl watched her sister's expression change as she moved from delight at the new size of her endowments, to discomfort at their new weight and springiness, to arousal at their newfound sensitivity, to fear at the thought of them growing even more!
Tiffany grabbed her jacket with one hand and ran out the door with her breasts cradled in the other. Where she was going, who knows? Probably to get some new clothes, Cheryl guessed.
However Cheryl didn't have time to gloat over her victory. She realized she was late for practice and left in a hurry. While she was gone...