I live in a single-parent household with my beautiful older sister, who is much older than me. One day, my sister saw me masturbating! "It's okay. There's nothing to be embarrassed about," she said, and helped me masturbate. I eventually wanted to have sex, so I asked my sister, and she said, "Just use your mouth. In return, you can move as you like." So I inserted my dick into her mouth and started pistoning at high speed, as if we were having sex! My sister must have been very excited, because with a look of ecstasy on her face, she said, "Let's do something more erotic."