The next morning I awoke at 6'6" tall, which made me feel more ready to face the coming day. My sister would be going to school with me. It turns out that I was lucky enough to only share one class with her: engineering, unfortunately, as my luck would have it. As we filed into that last class, I measured myself up against my group members. I'm pretty sure none of them were turned on right now, so I'd say it's a farely safe estimate. Abby and Jessica were both 5'1" tall, Hannah was 5'8" tall after the incident yesterday, and Natalie was down to 5'1" tall now, after she drank some of my juice from yesterday. My sister stood close to me, her diminutive frame hugging close to my seemingly massive one. Our teacher shouted, "class, this is Amber."  He paused as everyone clapped. "Amber, join group 1 with your brother, so he can get you up to speed."

I reviewed our project for her. Even as we were starting I could see her growing a little taller; probably one of her first times. We had barely started the project when Hannah walked up to me, wearing a skimpy skirt that perfectly accented her beautiful butt, at her full potential height: 6'4" tall. She was still wearing Natalie's heels, probably because she forgot to give them back yesterday, so she was 6'8", making me about eye level with her lips.

"Hey," she said, leaning towards me. I was ashamed to admit it, but she was really turning me on. I pushed her away before she caught on. I had to push a lot harder than I thought I would have, but I guess she was almost as tall as me now.

Hannah, unfortunately, noticed my slight change in stature. "Oh, you like them aggressive?" she asked, smiling deviously. "Well, let's gut busy then, shall we?"  With that, she grabbed my collar and began running me towards the wall. Once she slammed me into the wall, she began undoing my shirt. By the time she was done with the last button, I was 6' tall, a full 8 inches shorter than her, and eye level with her collar bones. She was undoing my belt when Abby cut in.

"Hannah," she said, using a strong tone. "You know what happens if anyone breaks any more rules, don't you?"  She had a hand on her hip, and was pointing sternly. Though she was stopping Hannah, I could tell she liked it.

"Calm your shiz," Hannah said, dropping my pants and walking away. "I just knew it was the fastest way to get him shorter. No more of this, 'I'll do it mysef' b.s. he's giving us."

"Ok, ok," Jessica said. "Well, you don't have to go all the way."

With that over, I was panting heavily, and basically fully shrunk. I walked over to Amber, who was 5'2" tall now. The top of her head was basically at the bottom of my lips. She was giving me the largest grin of her life, and I embarassedly shook my head and looked down, smiling awkwardly at her.

Today, the girls peaked at 5'9" tall for Jessica, Natalie and Abby, 5'5" tall for Amber, and 6'4" tall for Hannah. At the moment I was 6' tall. Abby pulled out her cups again and said, "You know what time it is, don't you?"

"Yeah, I guess so," I said, grabbing the cup and jacking off. Thanks to Hannah, I made quick work of it, and shot my load off in no time. As I did, I again felt the world spinning around me, with everything getting bigger. I realized once I was done that I had shrunk 10" again, down to 5'2" tall. My sister, who was younger than me by 3 years, laughed over me as she stood 3 inches talle than me, with my eyes level to her lips. For Jessica, Natalie, and Abby I was eye level with their collar bones, and for Hannah, I was eclipsed, even without Natalie's heels on. Without the heels, my head didn't reach over her shoulder, and my eyes were face first into the top of her cleavage. With the heels, though, I felt positively lilliputian. She was a foot and a half taller than me, and my eyes were burried in her cleavage. Then, Abby shouted "Another 10 inches loss for you!  Is that usual?" she asked, looking to the girls around us, who just shrugged. Then, she grabbed the smaller cups. She announced, "As a welcoming gift," and poured half of it in a glass and handed it to Amber. Then, she split the remaining bit among the other girls. They all leaned back simultaneously and took the shot. I would have expected Amber to have been more nervous about eating cum; especially her own brothers'!  The other girls each grew an inch, while Amber grew five. She stopped at 5'10" tall. For the first time in my life, I felt dwarfed by my little siter. As I thougt about it, this was around where she was compared to me two nights ago. I looked up into her eyes, and rather than her usual loving look, I saw dark, stormy eyes, filled with a thirst for power. She walked up closer to me.

"Hey big brother, how's the weather down there?"

"It's nice, thanks for asking."  I decided I'd play along with the joke. "Could you move to the left an inch or two?  That way your shadow blocks the sun."

"Don't be smart with me, little boy!" she said, wagging her finger condescendingly at me. I laughed, but looked up when I heard she wasn't. Her face was dead serious, and she was staring daggers into me.

"Woah, Amber!" I said, concerned by her sudden dominatrix attitude. "I've never been a bad brother to you!  What's going on?"

"Come on," she said, slapping my back more roughly than she probably meant to, "I was only joking!  Laugh a little, man!  Hah, little man, get it?"

"Hey, Natalie, can I get your wedges from Hannah?"

"Sure," she said, getting a little smirk on her face. "You can keep them, actually. I thought Hannah was going to steal them like she does with jackets, so I went ahead and got some new ones."

"Really?" she squealed. "Thanks!  Hannah, give 'em here!" She slid them across the room, and Amber put them on. In them, she was currently 6'2" tall, which was almost my old height, while I was 5'2" tall, almost her old height. I stood a foot under her and looked up. She looked down on me, loving it. Now the top of my head was at her collar bone, and my eyes were at the top of her still-developing breasts. With that, the last bell rang, and we got on the bus to go home together. Throughout the years, we had been far enough apart to avoid going to the same schools, but now, she came and sat next to me on the bus. Since she was sitting, the effects of the heels were cancelled out, but she still made me feel like an eight year old boy next to his mom. I was still having trouble wrapping my head around it: my 13 year old sister, who had barely entered puuberty, was 5'10" tall, while I, her 16 year old older brother, was 5'2" tall. While I was pondering this, she rested her arm on my shoulder, like some people do to be annoying. When I didn't push it off, she moved it closer and closer, until she had pulled me into a full-on sitting hug, with my head resting in her bosom. Once I realized it, I tried to pull out, but she held it there for a while, relishing her power. Once we reached our stop, I walked slowly so I could talk with some friends and get away from Amber.

"Damn, your older sister's sexy!" a friend of mine said once he thought she was out of earshot.

"What are you, a child rapist?" I asked. "She's 13, and she doesn't even have an ass or boobs!"

"What?" he asked, astonished. "13?  And, I mean, she will."  He saw the look of doubt register on my face. "No, look at her!  Long legs, a nicely shaped body; plenty of potential, if you ask me."

With that, the conversation stopped, because he had to head towards his house, and I towards mine.

When we walked in the door, you could've heard my mom gasping on the other side of the country. She stopped what she was doing, stopped us in the doorway, and looked at us.

"My baby girl!" she shouted. "What have you been getting into at your first day of high school?!"

"No, mom, I swear, it's for engineering, see?" she said, as she handed her the teacher's slip.

"If you say so," she muttered, angrilly crumpling the slip and walking away.