The events of that night were definitely pretty unusual, with Molly eating so much food and you noticing her recent development, but you quickly forgot about it when you went upstairs and began playing video games. Time flew by and before you knew it, it was 2:00 AM. You took off your headset and went to the bathroom to take a piss and get a drink of water before bed. While you were there, you head a weird noise coming from Molly's room. It sounded like heavy breathing. 

You pressed your ear to her door, trying to listen, and leapt back in disgust when you realized what she must be doing in there. No brother wants to imagine his sister pleasuring herself, though a part of you was intrigued. Her bed was making creaking noises, when all of a sudden the breathing and creaking stopped. Maybe she knew you were listening!

You went to bed and slept late the next morning. You saw that Molly's door was shut when you got up and it was still shut when you went down for lunch. Seeing it still closed at 3:00, you decided to knock. It was unlike Molly to be shut in her room all day and maybe it had something to do with her being embarrassed about you hearing her masturbating the previous night. 

"Are you planning on joining us humble mortals today?"

You heard the bead creak and the sound of footsteps approaching.

"Tim, I don't feel so well."

"Oh. You want me to get you some medicine?"

"No, I'm not sick. I'm just...."

You tried to open the door but found that it was locked. 

"Molly what's going on?"

"Promise you won't freak out, okay?"

"Fine. I promise. Will you just tell --"

You were cut off as the door opened and you saw your sister standing there. Well, it looked like your sister, except she was a half a foot taller than she had been the night before and now had a pair of real boobs, probably about a c-cup. She still had on the tank top from last night, though now it looked more like a crop top than anything. You looked up and down her body while she scanned your face, searching for a reaction to her growth. 

"H-how did this happen?"

"What do you mean?" she teased, winking at you. "Come inside. I'll explain."

She pointed to her bed and you sat down, while she went over to her drawer and pulled out two little pill bottles. You couldn't help but notice that her rear had grown into a nice little bubble butt. If she wasn't your sister, you'd seriously be eyeing her up. 

"So you remember my field trip to the chemical plant last week? Well, I brought home a few souvenirs and lets just say, they weren't from the gift shop." 

"You mean those pills are from GrowTech? That's how you got so much..."

"Bigger? I mean, can you blame a girl for trying? I've spent my whole life as a pipsqueak, underdeveloped and neglected by the puberty fairies. When I heard that they had a product to make you grow bigger, I jumped at the opportunity."

"But Molly! You don't know anything about these pills, I mean the dosages, side-effects, consequences!"

She shrugged and stretched her arms up to revel in her new height. "Maybe, but I feel fine. Fantastic, actually!" She gave her boobs a little pat. "Not complaining about these either." She saw you blush and smiled coyly. 

"What will mom and dad think when they learn their daughter has taken experimental growth drugs."

"That's the least of my concerns right now. Right now, I'm thinking about the fact that I'm starving. Growing girls gotta eat, you know! Why don't you go get me some food?"

"This isn't a restaurant, get it yourself!" Who did she think she was, bossing you around like that?

Molly looked upset at this response and scowled. She started to leave the room but turned at the last second. 

"I'd start being a little more respectflu to your 'little' sister, bro. I have a feeling I'm not done quite growing yet," she said with a smirk.

And with that, she left the room and images of a taller Molly filled your head. The thought turned you on, you had to admit, but it was still terrifying. You had to find a way to get those growth pills from her. Before she took it too far...