My seventeen-year old sister was having sex with a fourteen-year old boy, a boy in my eighth-grade class. She was a junior in high school, a senior ne...t fall.I was barefoot on the ladder so now my feet were hurting but the scene below in my sister's room was so exciting I couldn't stop looking. I did take the mirror away for a few minutes at a time, not wanting to get caught spying, but every time I looked, I felt a twinge in my panties it was so sexy.I had to get down and go pee at one point. She said the idea that I was watching her slowly began to appeal to her, and even more, eventually. She began to be quite titillated by it. One evening after she’d had a few drinks with the girls, she thought ‘Well I’m going to give this young pup a sight for sore eyes!’ I think that was the night she espied me and did a teasing strip and masturbation in front of the window. You can imagine that I nearly died of excitement. Thank god for the strength of young hearts. Very soon after this she. I was timid at first but quickly gave in and began aggressively kissing him back. We kissed and groped each other for a few minutes until we both couldn't take the waiting anymore. He slowly knelt down in front me, his face level with my cock which was about to burst out of my pants. He slowly undid my belt and pants, reached in and grabbed my throbbing cock. He looked it over, noticing and complimenting on how hard I was and the precum that was already leaking out. He slowly kissed and licked. I reached up, the tip of my phallus touching at her vagina.Then she reacted.Her hands shot down, trying to cover herself. I pulled back, then pushed forward again, this time worming underneath her hand. Only then did she understand what was happening. She could hardly swim and stop me, her species so unaccustomed to the water. I pressed my advantage, finding her opening.I slid underneath her hands, then past the bottom covering, prying up underneath the string and pushing underneath the.