I noticed the bathroom door was partially open and saw my sisters friend changing. She is such a hot eighteen year old girl. I could not help but to watch her. She totally busted me with my dick in hand. She freaked and told me she was going to tell my sister. I tried to bribe her but she was not having any of it. Then she grinned and asked to see my cock again. She told me to fuck her and it would be our little secret. I was in heaven. Her tight pussy fit so nicely around my cock. I thought she was a sweet girl,  but she was far from it. She was naughty and loved to be spanked. She did not even think twice when she got on her knees to catch my load all over her face.