At Home (Sister Route)

It all started right at the end of my senior year of high school. I was already 18 and graduation was a week off. Granted it was home school graduation, but oh well. My parents were out busy making preparations for a party to celebrate, and my sister Tabby was setting up decorations in the living room. I walked in from my room, taking in how awesome everything looked. It may be what I see every single day, but it seemed extra special that day. As I looked over everything, my eyes fell on my sister as she was reaching up to put a streamer on the wall.

Tabby is my older sister by three years. She's also the only other woman I've ever had any meaningful interaction with besides Mom. I've always liked the way she looks: long wavy blonde hair, striking blue eyes, and a slender 5'8" frame that compliments her 38C chest. She's always happy, always smiling. She's also, surprisingly, completely oblivious to the fact that I'm a futa. Yeah, hard to believe, but my parents shielded us both extremely well. Maybe not such a good thing in the long run, but that's how it was. Anyway, because of this, I never got any judgment from her.

This day, she was wearing some pink leggings and a crop top. I never truly thought anything about how she dressed... until right then. As she reached up to tape the decorations to the wall, her shirt slid up enough that I could see the underside of her breasts with no bra to hide them. Imagining those perfect tits in plain view got me wet and hard almost instantly. That brought me back to reality as I remembered she had never seen my dick before, and it was more than visible now. I quickly turned around and ran back to my room before she could see what I was hiding.

I closed my door and looked down. My dick was making my skirt stick straight out in front of me. If I didn't take care of it right then, I'd have it for too long of a while. I sat on the edge of my bed and lifted my skirt up, exposing my huge dick. I grabbed a box of tissues that were on my nightstand and sat them next to me. As I wrapped my hand around my dick, I started to picture myself being straddled by a hot, busty girl, my cock slowly being swallowed by her expecting pussy, her moans of pleasure as it inched into her. I started to stroke myself, timing it to the movements of the girl in my mind.

The girl moved on top of me, her hips rocking back and forth on my cock as I reached up to grab her tits, kneading them gently. Her eyes were closed in ecstasy, her mouth agape as she panted and moaned with each stroke. I could feel myself getting closer, so I sped up. I grabbed her hips and started to pound into her roughly, sending her screaming. Her tits bounced up and down as I rammed into her. I was almost about to let loose inside of her.

"Hey, sis, are you - WHAT THE FUCK IS THAT?!"

My eyes flew open as I heard those words, and I saw Tabby standing by my door, eyes wide in fear as she gripped the doorknob. At just that moment, I reached my climax and a huge stream of cum flew out, landing on her exposed stomach. I was horrified, both that I'd made a mess on her and that she had discovered my secret like this. I couldn't just sit there and say nothing, especially now that I had just cum on her. I thought for certain I was doomed.