"Alyssa, it's time for dinner!" Alyssa's mother called from down the hallway.
Alyssa gave a start, not realizing she'd spaced out while looking at the bizarre assortment of underwear on her bed. She quickly gathered them up and began cramming them into the top drawer of her dressed. She turned around and looked at her reflection in the mirror. A girl just over five feet tall, with light brown mid-back-length hair and a light dusting of freckles across her youthful face stared back. Alyssa ran a hand over her hips, pursing her lips and staring at the mirror. She had recently upgraded her bras from the training bras of 8th grade to more womanly underwires appropriate for a high school freshman. Her pert breasts filled the A-cups nicely, promising that soon she'd need to pick up a B-cup.
Her flat stomach flowed into her fairly narrow hips. Unlike her mother, whose wide hips and full butt Alyssa couldn't help but admire, Alyssa still looked boyish. "Maybe this year, though," she thought, turning sideways to see her modest rear profiled in the mirror. Then she glanced at her dresser to see a bit of the blue ruche-back briefs sticking out. She tugged them out of the drawer and held them up.
"Bootylicious, huh?" She muttered. "Well, what the hell." She slid off her plain cotton briefs and stepped into the blue ones. She felt a rush in the pit of her stomach as she pulled them tight, and her knees even buckled a little bit.
"Whoa... that was weird," she said. Her heart was racing a bit, like the times when a cute boy said hello to her at school. She turned sideways again and looked at her reflection. She was disappointed at what she saw. Although they fit her fine in the front and around the waist, the blue briefs were wrinkled and baggy in the butt. It was almost like they had extra material back there. Alyssa supposed they were made for girls with a more impressive backside.
"Alyssa! I don't want to ask again!" Her mother called.
"Coming!" She yelled at her closed door. She snatched a pair of soffe shorts from the floor, slid them on over the baggy briefs, tossed on a t-shirt, and headed down the hallway for dinner.
Alyssa took her usual seat across the table from her 5th-grade brother, Davis, and her 7th grade sister, Claire. Her mom was on the right and her dad on the left. The family ate and talked, mostly about the new school year. Periodically throughout dinner, Alyssa kept feeling that same whooshing feeling in her stomach as she ate. She even stuttered once when it happened while she was talking. Her mother glanced at her concerned, but she only said she was fine, then excused herself from the table.
As she stood and turned around, she bumped the table with her butt, causing her silverware to clatter.
"Haha, Alyssa's gotta big butt!" Davis taunted. Claire laughed along, peas in her mouth. Alyssa shot them a dirty look, then hurried back to her bedroom. She felt flustered, and not just because Davis had made fun of her. As she walked down the hall, she couldn't help but feel her butt giggle and sway in a way she had never experienced.
Arriving in her room, she shut the door and turned to the mirror. She gasped at what she saw. Her soffe shorts were noticeably stretched across her more ample bottom now. She pulled them off and turned her butt towards the mirror, eyes popping.
"My.. my butt!" She said, stunned. The panties were now stretched tight over her cheeks, every inch of the fabric full of her round yet toned rear. The ruche, which previously ran uselessly down the middle, now hugged her cheeks flatteringly. She had an ass that would rival Kim Kardashian!
Alyssa ran a hand over her newly expanded butt, feeling the real sensation. Just looking at her own reflection made her feel a little warm in the crotch, for some reason. As she looked, she felt another swooshing sensation in her stomach, and had to restrain a yelp of surprise as she watched her ass expand further, bulging out against the fabric of the panties even more.
"No! I don't want to be a freak!" She said, panicking. She bent over and yanked the panties from her body. All at once, she felt a wave of nausea overcome her. She clenched her stomach, feeling as if she was going to throw up. Then just as quickly as it had come, the sensation passed. She straightened up and looked at her reflection. Her butt, now bare, was the same size it had been before dinner.
Alyssa looked at the Bootylicious panties lying in a pile on the floor, something clicking in her mind. What should she do now?