If there were one word that could sum up Ashely's body, it would have been "flat". The poor girl had been cursed with a boyish figure. Most notably was her notoriously small chest; at a bra size of 32-AA, she'd had already been outgrown by her younger sister Lisa, who was fast approaching a B-cup. In truth, her small size was the main reason she hadn't been wearing a bra when Matt had shrunk her. The only upside to her tiny tits that they were well suited to her softball team's cardio-intensive exercise routine, though that hadn't stopped her from envying her bustier team mates.
Matt was well aware of her insecurity. Ashley had never attempted to hide it after all, often discussing her disappoint with Lisa and her mother. Even to the point of asking for breast implants as a birthday present. Her mother refused, of course, but that certainly didn't stop her from asking every year. This gave Matt an idea: why not give her breast implants? She was likely to accept it after all and he was actually curious to see how it'd work. With Ashley finally in position on stage, he made the proposition.
"Alright Ash', it's time to solve your confidence problem. Let's say I pay you twenty dollars and you let me grow your tits like you've always wanted?".
Her eyes lit up like spotlights at the suggestion. "Seriously? That would be soooo cool! Mom 'n Lisa couldn't make fun of me anymore. Alright, you can do it."
As Matt readied the bracelet, he hoped his sister would enjoy her implants, considering he'd never mentioned they'd not be "homegrown" as it were. Following earlier success, Matt simply wished that Ashley would get C-cup sized string implants. Instead of the gradual growth they had expected from the earlier example, the two were greeted by an explosive growth as the implants instantly formed within her breasts. The strong material of her bikini top was able to hold, just barely, against the powerful force of her expanded bust. The fabric clung tightly to her skin, barely covering her nipples as the rest of her bust bulged from its AA sized encasement. As expected, there was now a noticeable gap between each breast, an obvious indicator to anyone of her new implants.
As the initial surprise wore off, Ashley could hardly contain her childish excitement. She began to play with her tits, bouncing and groping them without even realizing Matt was still there. Not that he minded; watching Ashley play with her new tits was pretty hot. Even more exciting was the prospects it contained. Because they were string implants, they were bound to grow over time, taking her C-cups to unknown sizes. With her enthusiasm wearing down, Matt began to think on what to offer next, assuming she'd accept it.