After school, she enjoys riding my sister's partner's penis while our fathers are away

After school, my 18-year-old girlfriend and I were in the mood for some fun. I had a wild idea that I had been thinking about for a while. I had heard that my girlfriend had a thing for uniforms, so I thought it would be fun to dress her up in one of my sister's partners' outfits. It was a bit risky, but it was worth it. She looked hot in the tight pants and shirt, and she loved the way it made her feel. We went back to my place to continue our fun. I asked her to ride my cock while we were waiting for our fathers to come home. It was a bit strange to be doing it with my sister's partner's penis, but it turned on both of us. It was a wild and fetishistic experience that we both enjoyed.