I was 14 at the time my step sister was 15. Her room was next to mine I often heard her masturbating in her room and I used to masturbate while listening to her climaxing. I had some of the best climaxes ever and my sheets used to get so wet and sticky as a result.
One night I was woken up by her getting into my bed. She said she was horny and she wanted to feel my cock inside her. I was scared we'd get caught but I got so horny I couldn't resist making love to her in my bed. She came quickly which was good because I couldn't last very long and I came deep inside her two minutes later and she had a second orgasm.