“Mitch! Mitch!” My bratty little sister shook me awake.

“Wha? Waddya wann…” I was still mostly asleep.

“Can I sleep with you? Pleeeease?”

“What? Why?”

“I’m scared! The storm!”

I noticed the wind whipping the trees and making the house shudder. It was a bad one. I smiled at her.

The truth is, I LOVED a good storm. If tomorrow wasn’t a school day I would be outside right now enjoying the show – the sight, the sound, the smell, and the feel of it. On the downwind side of the house, though… no reason to get soaked when I didn’t have to. I listened to the wind howl through the trees, and make that classic spooky wailing sound through the power lines.

The last time Kelly needed company was a couple years ago. Our parents wouldn’t let her sleep with them, chiding her for being a baby. So she came to me and made me promise not to let them know.

And here she was again.

I threw open the covers and moved over to let her in. The small, twin-size bed was barely big enough to hold us it seemed. I guess that’s what happens when you grow up.

Kelly snuggled up to me and I spooned her. I put my arm around her and she immediately grabbed my hand and clamped it to her chest. And I felt… BOOBS. Where did those come from? They were small, yes, but they were definitely there. My bratty little 13-year-old sister was growing boobs.

It was just a couple months ago we were messing around in the back yard. We got really dirty and we stripped down to our undershorts so Mom wouldn’t yell at us for bringing the dirty clothes into the house. She didn’t have boobs then. At least she didn’t look like it. Can boobs really grow that fast? Maybe they were there but just didn’t show.

I didn’t have to hold her as she was doing all the holding. I drifted off to sleep.

I awoke later to feel her pulling on my arm. I had rolled over, now I was at the edge of the bed and her back was pressed against mine, nearly pushing me off the edge as she grabbed at my arm.

“Mhuh? Wha?” I said, half asleep. The storm was still raging outside.

“Come back!” Kelly whispered urgently, “Come back here!”

I realized she want me to spoon her again.

I also realized I had a very hard boner.

“I can’t,” I mumbled.

“What? Why not?!”

“I have a boner,” I tried to speak more clearly.

“So?”

“I don’t want to, um, stick you with it.”

“I don’t care!” She was tugging now.

My sister didn’t care if she felt my dick against her? I rolled over and spooned her again, but before I settled in I pressed my dick into her tailbone, “Do you want it here? Or…” quickly bending it down and thrusting my hips toward her so it was pressing up against her crotch, “…here…?”

“That’s fine,” she said, still whispering for whatever reason as she grabbed my hand and again pressed it against her chest. Boobs.

She couldn’t see my eyes pop open. I was expecting her to get all pissy with me, but instead it was fine that my hard cock was pressed up against her cunt.

I was drifting off to sleep again when the thunder rolled over. Loudly. I felt her body quiver. And I felt her cunt twitching against my cock, through the layers of our underwear. Then it happened again, not quite as loud, but longer. Her cunt was jerking against me along with the rest of her body. I hugged her to me and she squeezed my hand tightly.

It was at that moment I realized that my little sister was a girl.

I guess up until then I had thought of her as a kind of… animal. And not a very tame one. Maybe it’s that way with all little sisters. They’re just not really people.

It thundered again and I started thrusting. Slowly, just a little bit. But it seemed to calm her. So I kept it up. When the thunder came again I thrust a little more, but still slowly. Her grip on my hand loosened as she snuggled into me. I started gently rubbing and squeezing her little titties.

Now that I felt them, they were indeed small. That was probably why she still didn’t wear a bra, but that was none of my concern. I had thought all girls wanted to wear a bra when they were ten, but she didn’t. Maybe Mom wouldn’t let her. Whatever.

That went on for a few minutes. I guess as long as I did it slowly enough it would calm her down instead of excite her. I eventually stopped and slept again.

Briefly.

It thundered again and Kelly had woke me by jerking and yanking on my hand. I hugged her to me and made thrusting motions even though my dick had gone soft. I did that for about five minutes and then drifted off to sleep.

I awoke a few hours later with a boner again, riding up her back. I bent it down again and began the slow thrusting I had done earlier. The storm was dying down, but Kelly still held my hand to her chest. Though not so tight that I couldn’t rub and squeeze.

I was a little more awake now so I humped her for about ten minutes. Then I extracted my hand and backed away slowly to get out of the bed on the other side.

“Where are you going?!” Kelly whispered fiercely as she gripped my wrist and tried to pull me back.

“I have to go to the bathroom,” I explained. “I’ll be right back. I promise.”

She whimpered like I was leaving her forever. But she let me go.

My dick had gone down enough that I could bend it downward and piss into the bowl instead of all over the wall. I flushed and washed and went back.

Instead of going over to the other side of the bed, I lifted the covers on her side. She was still curled up. I swung my leg over her and squatted down, pressing my half-hard dick into her thigh. I bent over her and, supporting my weight with my elbows, lowering my chest onto her arm that was against her ribs. I adjusted myself so my head was even with hers and kissed her gently on the cheek.

I just laid on her like that for a minute, feeling her breathe. Then I kissed her gently again and whispered into her ear, “I love you, Kelly.”

She made a little “Mmm” noise.

Then I slid off and resumed my spoon position behind her. After everything we had done together so far, I figured it was no big deal, so I slid my hand right up her night shirt, feeling her bare tits. She sighed softly and snuggled back into me, only lightly pressing my hand.

My dick was soft, but I pressed it up against her anyway. After a few minutes I drifted off to sleep again.

In the morning the storm was waning, almost gone, and somehow the light made it far less intimidating. Kelly was lying on her back, staring at the ceiling. I snaked my arm under her neck and put my hand on her shoulder. She rolled over, half on top of me as I rolled to my back, snuggling her head on my shoulder and straddling my thigh. I felt moistness as the crotch of her panties pressed into me.

We just lay there for a while, my arm wrapped around her. Then Kelly pushed herself up off me.

“Thank you,” she smiled and gave a quick smooch on my lips. And made sure I got a good look down the front of her night shirt.