Disclaimer: This story is purely fictional and intended for entertainment purposes only. Everyone in this story is a consenting adult over the age of 18.
The next morning, which was a Saturday, dawned bright and sunny. If the hardness of my dick was any indication, it was going to be an awesome day. Even better than the evening before, when my four siblings and I got off while watching my parents masturbate each other!
I hopped out of bed, my cock bouncing excitedly, and stretched. Boy was I looking forward to this new stage of life. All the sexuality I was going to explore was stimulating beyond imagination. I headed for my bedroom doorway, not bothering to get dressed. My whole family stayed naked most of the time, anyway, so that was nothing new. I entered the bathroom and brushed my teeth to get rid of my morning breath. Then I jacked off into the toilet to get rid of my morning wood. Just as I was starting to think about cumming, my older sister Britt walked in naked. Her pussy glistened with her own excitement, and she gave me a big "bare" hug from behind. I could feel her wonderful, perky B-cup tits pressing into my back while she ground her pussy into my butt. That sent me over the edge, and I groaned in ecstasy as I shot stream after stream of cum into the toilet.
"Did you like that, Brock the jock with a sexy big cock?" she said quietly into my ear.
"Oh, yeah, that was awesome!" I replied exuberantly. "Feeling your naked boobs against my back was incredible!"
"Want to help me out now?" she asked coyly, pinching her tits and biting her lower lip.