My step-sister has always been a bit of a wild child and she loves to do things that push the boundaries. One of her favorite activities is riding my big cock.It all started one night when I was in my bedroom and she came in wearing nothing but a skimpy pair of panties. She had a naughty grin on her face and I knew she was up to something. She said she wanted to try something different and asked me if I was up for it. I was a bit hesitant at first, but I decided to go along with it.She straddled me and started to grind her hips against mine. I could feel her tight pussy pressing against my manhood and it felt amazing. She started to move her hips faster and faster and before I knew it, she was riding my big cock like a pro.I felt like I was in heaven as she moved up and down my shaft and I felt my orgasm building up inside me. When she finally let me cum, it was like an explosion of pleasure that I had never felt before.Since that night, my step-sister has become an expert at riding my big cock and I can't get enough of it. She loves the way it feels and I love the pleasure that I get from it. It's become one of our favorite activities and I wouldn't trade it for anything.