It was a late summer evening and my wife had asked me to deliver some paperwork to my sister in law that she needed for work. My sister in law lives about ten minutes away and I figured I'de go out for some cool air. My sister in law Sarah is a very attractive woman, she is very short so that makes the rest of her body look very big. She has full breasts and a very nice round ass. For a few years now I have fantasized about making love to her. You see, her husband has been a real jerk to her according to my wife and the rest of the family. It seems that they prefer that they seperate so that she can be happy with someone else. I was on my way with the documents and parked accross the street. I approached their property and noticed the living room lights being turned off. I came up on the drive way and hesitated. Should I ring the door bell or go knock on the window which was closer to me and still had the lights on. I did not want to scare anyone so I quietly walked towards the bedroom window that was open to let some of the summer evening air in. I could see shadows moving behind the sheer curtains. I came up against the window and took a peak in. Oh my! Before I could make myself be heard, Sarah walked into the bedroom taking off her burgandy colored nightgown. She stripped before my eyes and my heart stopped. Her husband it turns out was the one walking around in the room and already in bed. With my heart pounding and my heavy breathing I did everything possibe not to be heard. I could not believe the breasts on Sarah. They were very large and white with soft pink ariolas. They swayed as she climbed on the bed and over her husband Joe. I stood frozen looking in. Sarah pulled down Joe's briefs and unleashed his manhood. Oh my! Now I know why this woman does not leave him. She took hold of this rather large and thick piece of meat and began to stroke it and slowly put the head in her mouth. His dick began to respond and grew in her mouth as she gave up trying to take it all in. From the closet mirror I could see her licking most of its length and jerking it back and forth. I could see her saliva glistening over the tip of his swolen head and noticed that my own cock was ever so hard. I was transfixed to the images of Sarah and Joe. What to do? I quietly walked away and back to the car. I sat for a few seconds and figured I would never get another chance to see this again so I removed my belt from my shorts as to not make noise and grabbed some fastfood napkins I kept in the car. I trotted to the house and walked quietly as I approached the window. The curtain blowing ever so slightly from the breeze of the rotating fan in the bedroom. When I looked in Sarah was taking all of Joe and riding him in rodeo fashion. Sarah would raise her hips up into the air and I would see her pussy lips being turned inside and out. She would slam on his dick and raise herself up again and do some circular motions before taking all of his length. He must of been about ten inches and I was amazed at how this little woman was man handleing it. I could see the extasy in her face as she would bite her lips everytime she went all the way down to his balls. My eyes were fixed to the reflection in the mirror as she would bounce on him and let him grab her nice breasts. With her pussy lips being pushed in and pulled out by his dick he grabbed her waist and rolled her over. Never taking his dick out of her. I was shocked. He reached for her legs and put them over his shoulders. Now my eyes were fixed to his ass as he slammed her for all he was worth. And he was worth a lot by the sounds of things. He plunged into her and now with my own dick in my hand and stroking not caring how much noise my well lubricated dick was making. I came way before he did, as much as I tried to hold on, the images were just to good. She was moaning trying not to be loud as the kids were in the next room then she pulled a pillow over her head. He moved faster and deeper if that was possible. I could see his dick was very slick from all her wetness as she raised her hips to meet his every thrust. He unloaded inside of her as he groaned and pushed all the way in. She wrapped her legs around him in a vice and they kissed passionately. When he pulled out of her his dick looked enourmous as it plopped out. She reached for a towel on the night table and wiped his dick clean and lovingly kissed it. She walked out to wash up and thats when I walked around to car for the documents and rang the doorbell. I said I was gonna drive off but I saw the lights were still on and she thanked me for the documents and I was on my way.