Dear diary: I have always been a very shy girl, and my older sister Emma was the outgoing cheerleader in the family. Every now and then I`d catch glances between her and our step-brother, but I was too naive to see the truth. But when I saw Emma fucking Step-daddy, I became so aroused I could barely control my desires! One weekend I went with him to the lake house. I couldn`t contain myself once we were alone and confronted him with what I had seen. Daddy thought I was going to blackmail him at first, but once he saw my true intent, he was perf..