My wife and I have been married for twelve years. My sister-in-law was seven when she was our flower girl. The past twelve years have seen her blossom into a beautiful young woman. She was the home coming queen, the whole bit. At 5' 5", blonde, a hundred and ten pounds, and a 34C, she is athletic and sexy. As her brother-in-law, I watched her grow up, and lately she has busted me gazing at her fantastic body. She just smiles and doesn't seem to mind. Three months ago, we were visiting when a winter storm that developed further into a blizzard prevented my family from driving the forty-five miles to our home. So, we welcomed the invitation to stay at the in-laws’ house. My wife and in-laws turned in early. I stayed up to watch some TV in the basement family room. My sister in-law’s bedroom door opened off of the family room. The door was open just a couple of inches and the lights were on, but I was into a TV show that eventually lulled me to sleep. I woke quietly when I heard the TV being turned off as well as the family room lights. Silhouetted against the light from her bedroom door, I watched through slit eyes as she passed in front of the couch where I now feigned sleep. She was wearing a white, thin, nightshirt. As the light shown through, it allowed me to see her form as she returned to her room. I have to admit, I was getting excited as I lay there. She closed the door only slightly, but I still had a commanding view of her room. On the wall of her room is a full length mirror which just happened to expand my view of her room. Through this mirror, I saw her heading back to the door where she just stood and watched me. I tried to maintain a slow, steady breath rate and my eyes opened only enough to be aware of her presence in the door. I watched as her hand dropped to the hem of her shirt. She pulled up the hem and exposed herself and then backed into her room again. A few minutes later, she reappeared and tip-toed across the room to where I was laying. As she pulled the shirt up exposing herself, I stirred. She panicked and backed into a coffee table and then lurched forward and fell across the couch right on top of me. Now I was fully awake. She quickly wriggled to her feet as I asked what had happened. She made up the excuse that she was going to see if I needed a pillow or blanket and tripped on the table. That’s when I told her I had been watching her these past several minutes and immensely enjoyed seeing her body. That’s when she surprised the heck out of me by telling me she had had a crush on me for as long as she could remember and often fantasized about being naked with me. I took her hand and pulled her back down on top of me and gently put my arms around her and held her to me. I felt her body relax from the embarrassment. She smiled at me as she settled on top of me. As our bodies touched, there was no doubt that she felt my excitement pressing against her tight belly. She smiled at me and said she wanted the whole fantasy. We kissed and got as close to intercourse as two people can get. She whispered that was a first for her and then collapsed against my damp chest. A few minutes later, she told me she would like to accomplish another first, and she proceeded to give me oral. I was nearly unconscious from ecstasy. We lay entwined until I began to nod off. My last memory was her silhouetted body slipping into her room. It has remained our secret to this day.