He said that since he saw his older sister sucking a guy's cock at a friend's he couldn't stop thinking about it. The best part was that his sister also saw him while she was busy sucking the guy's dick. Later when she finished she told him that if he be a good boy she would do the same for him. She took advantage of that. For a week of so he picked up her laundry, washed her car, go shopping with her. Made their parents go crazy, they thought he was sick or something. But then the day came and he recorded it.