My sister is a year or so older than I am. She developed as a teen and ended up with a body that constantly drove my cock through my denim jeans. One day, when I was 16, we were alone in the house and I had a boner that shocked me to look at it since it looked like someone else's, it was so large. It was also hot and almost glowed like a bulb.

I walked in front of her closed bedroom door, enlarged, bursting cock in hand. Then suddenly her door flew open and she saw my cock with huge, open eyes. It's like time stopped. Somehow she knew I was out there but the size of my cock startled her. She reached out and took my cock in one hand, touching it lightly with her finger tips, fondling it a bit and it exploded with cum all over her hand, blouse, jeans, spraying white strands of cum all over. I recall the huge pulses starting at my sizzling ball sack.

She went and got a towel and began to clean it up. The only words she said were, (quietly) "Don't worry about it." and that was it. All the years that followed, we never spoke about it but I knew that with little effort we would be fucking each other like crazed pups. It just never happened.