Background: The names in this story have been changed to protect the identity of those involved. Those involved in this story are me, John; my sister, Jessica and her boyfriend, Michael. I was 17, she and her boyfriend were both 16. They had been dating for a couple of months at the time these events took place. Knowing my sister, I would not have imagined that she would do anything beyond kissing, seeing as how she is fairly conservative. I, myself, was also fairly conservative and had not done much either. I came home late after school one day, probably around 6:30 and immediately made myself a snack and sat down by the computer to check my e-mail. As I was reading I could hear the movie that my sister was watching up stairs with her boyfriend.

Fifteen minutes passed and then I heard something else; I heard someone moaning in pleasure. I told myself, “Oh it’s just the movie”, but I knew it wasn’t. The moans became louder and more frequent and I could feel myself begin to harden. I told myself that this was wrong and eventually the feeling went away, but I had to find out what was happening up stairs. So I slowly crept up the stairs and as I passed by the couch they were laying on I noticed Michael laying on the couch and my sister’s mouth bobbing up and down his cock. I could tell I had surprised them, as my sister quickly stopped and he covered himself up. I didn’t say a word, I just went to my room.