Ally was a little annoyed that Kelley had passed her by so quickly so she could take a bath. It seemed that Kelley never had time for her anymore. She was always off with boys doing...whatever big girls and boys did. Ally didn't know what that was, but apparently Kelley did it a lot. The 15 year age-gap between the sisters made it almost impossible for them to bond over anything. There were more than a few times that Ally wished Kelley was younger or that she was older so the sisters could do more things together.
Though since Kelley obviously didn't want to hang out with Ally right now, the best thing Ally could do was imitate her. She looked in the shopping bag that Kelley left on the kitchen table and found a bottle full of pretty blue shampoo. Since Kelley was using the upstairs bathroom, Ally took the shampoo bottle to her mom's bathroom downstairs. She started the water going in her mom's Jacuzzi before looking in her cupboard for any bubble bath. It was the same bright blue as the shampoo, so Kelley poured some of both into the water. The bubbles foamed up faster than Kelley had expected, covering the surface of the water with countless blue orbs. By the time Ally had taken her Snow White dress off, the water was high enough and she climbed into the Jacuzzi. She giggled as the bubbles tingled against her skin. For some reason, the bubbles felt better than they usually did. She reached up and pressed the button for the water jets. She giggled some more as the water started pushing against her body. The sensations were so much that she didn't notice when she started growing.
But after 4 minutes, Ally started noticing that her thoughts were becoming a lot more developed, the games and lessons she remembered from her 1st grade class seemed a lot more childish. It was then she noticed that her hands looked bigger with slimmer fingers. It didn't take her long to notice how much of her body was filling the tub. "Am I getting bigger?" she asked, her voice sounding different too.
Then Ally felt a jolt through her body, something completely unrelated to the bubbles or the water jets. She could feel her body growing out in all directions as more information entered her mind, making her just as smart as any 11-year old. "I'm not just getting bigger," she said, her voice sounding a little different, "I'm getting older." She cleared away some of the bubbles from her torso to get a better look at herself. Her body was definitely bigger now, the baby fat she had melting away. Ally also noticed that her nipples were standing straight out, looking darker than they had when she got in. The area around them was also getting puffy. "Are those what I think they are?" asked Ally as she felt her chest.
Then another spurt of growth hit her and her body stretched out more. Ally gasped as she felt the mounds push into her fingers as she grew, sending pleasurable sensations down to her groin. Her mind was supplied new information to tell her exactly what she was feeling and why. It would seem that puberty had decided to make Ally an early bloomer. Ally moaned as she kept feeling her budding breasts. One hand slid down her side and under the water. She soon found her pussy and was briefly surprised to feel hair there. But soon she inserted her fingers and started stimulating herself.
Ally groaned as she pleasured her body for about two minutes. Each surge of growth made her moan in a deeper voice. The breast she was still feeling was becoming larger and rounder in her hand. She could feel her limbs taking up more space in the tub, pushing up the water level with her increasing mass. She rubbed faster as she felt the peak coming. Then she was hit with another surge of growth, boosting her sensation over the edge. She gave a small cry as she felt her body spasm and quake.
Ally sighed as the tension left her older body. She looked down to see a sizeable pair of breasts sticking out of her chest, but much of the rest of her was hidden beneath the water and foam. She felt the urge to see the rest of herself and climbed out of the water, turning off the water jets as she did. she walked over to the mirror and got a good look at herself. "Wow, I'm cute," she said in a teenager's voice. Staring back in the mirror was a 15 year old girl with black hair in pigtails. Ally felt a little annoyed with herself for leaving her hair in a childish style and reached up to pull her hair out of the pigtails. Unbound, they reached her shoulder blades. The rest of her body had grown quite a lot. She now had long elegant arms and legs that curved at the thigh before tapering down to small feet. Her torso was an impressive hourglass considering her age with wide hips, a plush rear, a trim waist and a pair of breasts that looked like they could easily be in the upper B's.
Ally looked at herself from different angles, taking in the sexiness her body now had. She remembered seeing pictures of herself as a newborn baby with Kelley also in them. Kelley had clear signs of the attractive woman she'd grow into, but Ally was obviously sexier than her sister was at 15. "I can see why the boys pay so much attention to her," said Ally as she turned to look at her butt. A bit of blue at the corner of her eye made her look back at the tub where the bottle of blue shampoo still stood. Her expanded mind quickly deduced that this shampoo was what caused her to age up so quickly. She grinned as she walked over and picked up the bottle. "Let's see if they'll pay as much attention to me when we're the same age," she said.
Instead of getting back into the tub, Ally walked into her mom's shower. She wasn't completely sure how this shampoo worked, but she'd rather not get older than she wanted to. Before, she wouldn't have been able to even reach the shower control. Now, she easily switched it on and allowed hot water to cascade over her naked body. Ally gave a sigh before squirting some shampoo into her hand and lathering it up in her hair. She soon felt a tingle throughout her body and leaned against the wall of the shower.
Ally didn't have to wait long before her body started growing again. She felt the surge as her limbs extended further. She particularly felt her breasts jump up a size. "Ooh, looks I'm going to get more stacked," she said as she felt her larger breasts. She squeezed them in her hands until she felt them grow again. By now, they were the same size as Kelley's, each filling up her hand. And yet, when she felt another surge of growth, they inflated even more. "Damn, Kelley. No wonder you were able to lay so many guys," moaned Ally. The mystery of what Kelley did with all those boys was no longer a secret. Ally's expanded mind had filled her in all about sex and the pleasure she could get from it. She moaned as she started fingering herself again. She could imagine a handsome man giving her a similar treatment before pounding her with his thick cock. Ally groaned as she masturbated harder, her legs buckling a little. And yet, she remained upright as her body grew out of the last of her teenage years and into her college years. "Ooh...yes, yes, yes!" she gasped, her voice fully mature and sensual. She let out one last gasp before she came again. She dunked her head under the spray of water, clearing out the shampoo suds from her long luscious hair.
As soon as her hair was clear, Ally turned off the water and stepped out of the shower. She could instantly tell that she had gotten noticeably taller and her body swayed from her increased curves. She walked over to the mirror and said huskily to her reflection, "Ooh, baby, did you grow up." Ally had been a rather cute girl at 15, but now she was an incredibly sexy 21-year old woman. What lankiness was left in her limbs had filled out with lithe muscles and substantial curves. Her hips were very wide and rounded with a soft patch of black hair between her legs. She turned around to look at her ass and saw that it was a perfect heart-shaped tush. She groped her cheeks, feeling a good amount of jiggle, but firmness beneath it. But that was nothing compared to her breasts. They had easily doubled in size from her 15-year old self. Ally grinned widely as she felt her expanded globes. "These girls are rated E for 'Enormous'," she purred. She looked again at her face in the mirror, marveling how a few years had changed it. Her face was a mature oval with a soft chin, plump lips, demure cheekbones, and eyes that sparkled with lust and excitement. Her long black hair framed it perfectly and added more to her beauty.
"Wait until Kelley seems me now," said Ally as she posed in front of the mirror. She couldn't wait to see how jealous her sister would be when she saw that Kelly had a bigger rack than she did. But even though Ally wanted her sister to see her adult body, she didn't want to show all of it. She glanced down at the dress she had been wearing earlier and laughed. That little thing could barely go up one of her legs, let alone her whole body. But her mom ought to have something appropriate for her new self. Ally walked into her mom's closet and looked around. There was plenty to choose from, but she wanted something sensual. Eventually, she found a black short silk bath robe and tried it on. It hugged her body closely and made a lot of her cleavage visible. Ally looked in the mirror with satisfaction, it was perfect.
Ally headed upstairs, hoping that Kelley had finished her shower so she could see how her little sister had grown. Ally raised a hand to knock on the door when she heard something inside. It sounded like a little girl's voice sobbing. "Kelley, are you ok?" asked Ally, her smugness replaced with concern. There was a splash followed by the sound of the little girl crying and struggling. Ally quickly tried to open the door, but it was locked. She rushed back downstairs and looked around until she found the house key. She raced back upstairs. As she fitted the key to the lock, the girl's crying had become higher-pitched and was sounding a lot less articulate. Ally quickly turned the key and threw open the door.
Instead of finding Kelley, all Ally found in the bathroom was a baby girl splashing in a tub full of soapy water, trying to climb out. Ally quickly fished her out and dried her off. The baby looked no older than a year old and her remaining hair was a mousey brown instead of blonde, but Ally was very certain who she was. "Oh Kelley, is that you?" she asked. The baby gave her a blank look and responded with infantile gibberish. By the looks of it, her mind was in the same state as her body.
"Don't worry baby, I'll look after you. Big sister Ally is here for you," said Ally comfortingly as she held her regressed sister close. She looked around the bathroom to see what could have caused it and her eyes spotted a bottle of purple shampoo. It seemed that Kelley had used a shampoo that had the opposite effect of what the other shampoo did. But there was still plenty of blue shampoo left, including a Jacuzzi full of blue foam downstairs.