While most people relished Saturday mornings as a chance to sleep in and relax, your parents saw it as the perfect time for cleaning out the house. It was not uncommon for you to be woken up by the sound of a vacuum cleaner outside your door or pots and pans rattling in the kitchen sink downstairs. On this particular Saturday, you tried to ignore the sounds of cleaning, but were called to action by a knock at the door.

"Time to get up, Tim!" your mom called. "You know the drill."

You grumbled and rolled out of bed. You opened the door and saw her standing there, her head just below your shoulders. She handed you a cleaning bottle and roll of paper towels.

"You can get started in the bathroom. I've asked Molly to do the hallway."

You set to work cleaning the bathroom and heard Molly humming to herself in the hall. All of a sudden there was a little knocking on the bathroom door.

"What do you want?" you asked her.

"Just checking in," said Molly. She seemed like she knew something because she didn't usually act so mischievous. 

"What? Did something happen?"

She must have sensed your suspicion because she gave a coy smile and left without another word. Honestly, sometimes she could be a bit weird. She was probably just trying to push your buttons so you'd get upset and wind up being forced to do her chores too.

That afternoon, after the house cleaning was finally done, you were plopped in front of the TV, watching a hockey game. Your parents had left the house and weren't going to be back until Monday morning because it was your mom's old college friend's 50th birthday. That meant it was just you and Molly for the next two days. It wasn't uncommon for your parents to leave the two of you at home, especially now that you were both old enough to drive and take care of yourselves.

You noticed Molly's reflection in the TV as she came up behind you.

"Hi-ya," she said. You grunted in response."What's for dinner?"

"Mom said we could order a pizza."

"Mmmm good. I'm starving!"

"Oh yeah? You're usually not too hungry."

"Guess my appetite has grown today," she said laughing to herself a little. You tore your eyes away from the game and looked at her. She wasn't wearing her usually baggy t-shirts or sweatpants. Instead, she had on a tank top and cutoffs.

It must have been a while since you saw your sister in such tight clothing because her chest looked a little bigger than you remembered it. She'd always been so underdeveloped that she never even wore bras and she wasn't wearing one now, though it looked like she could use it.

You must've looked a few seconds too long because Molly clicked her tongue and when you looked at her face, her eyes were locked on you. Oddly, though, she didn't seem too mad. She went into the kitchen and poured herself a glass of water.

You didn't pay any attention to this, but if you did, you would have seen her tossing back two more of the GrowTech pills she'd stolen.

After taking them, she came over to the couch and scrolled on her phone, glancing at the TV now and then. Your team ended up losing and on that note of frustration, you turned off the screen. Molly looked up.

"Pizza time?"

"Sure," you said. "How about a large pepperoni?"

"Make it two. And can you get the garlic bread bites too?"

You raised your eyebrows. "I don't know Mol, that's a lot."

"Just order it."

You were surprised at the tone of her voice. It was oddly commanding for someone who'd been so timid most of her life. You obliged and ordered it, figuring you'd have the leftovers for lunch tomorrow.

When the doorbell rang 30 minutes later, you went to the door while Molly grabbed plates. She licked her lips and bounced up and down as you brought the pizza in. Without waiting, she grabbed two slices and started devouring them. It was a bit distracting seeing her eat that fast. You'd never seen her that hungry and to be honest, it was a little disconcerting.

"You ok?"

"Mmmph.. never... mph... better!" she managed to say between bites.

You shrugged and chalked it up to her not eating much throughout the day. As Molly went in for round two, you noticed that her tank top was riding up a bit, revealing her taut stomach. That was weird because earlier in the day, it had seemed to fit her fine.Not only that, but her tiny, but present, boobs seemed bigger too. They were about the size of clementines, at least an A cup of B cup. That didn't seem right -- she'd had no boobs to speak of a week ago! 

Thankfully, Molly didn't catch you staring at her chest this time and she seemed oblivious to her recent development. She grabbed her 5th and 6th slices and went upstairs to her room to finish them. She also brought the box of breadsticks with her too. At last it clicked -- she was having a growth spurt! The increased appetite, the clothes not fitting, it all made sense now. You felt happy for your little sister, knowing how long she'd waited to go through puberty. Maybe this would help boost her self-esteem and help her feel more like a teenager.

Little did you know that this wasn't a natural growth spurt. It was something brought on by Molly herself. Something she was fascinated by and would soon be addicted to. If you had known at the time what was happening, you might have had a chance to stop it. To avoid the irreversible changes that would come. But you did not know. Nobody knew, not even Molly herself...