I take an almost daily run through the neighborhood. My route goes through the town park and by my wife's younger sister's apartment. My sister-in-law was in her mid 20's, unmarried, blond, and very trim. She went dancing to the bars weekly. One morning when passing my sister-in-laws apartment I heard my name called. I stopped and waved. She waved me to her apartment. I went in and sat down in a chair and was drinking water. We had small talk about my pregnant wife and 2 yr old son. My sister-in-law stood up and held out her hand and said I was going to finish my exercise a different way. We went to her bedroom and undressed. I apologized for being sweaty. She said just like her dancing friends. She dried me with a towel and started give me an 1st class blowjob. I was about to cum when she pushed me on her bed. We both must have wanted each other s long time. I would like to say that I fucked her but she fucked me. She was awesome. This started an almost daily escapade. If her sliding door curtain was open I would enter. She kept a shaved c**t and loved for me to go down on her. She was an athletic fuck. After a few weeks she told me she was pregnant. I never asked her about protection and feel she got what she wanted. We both think I'm the father. I had been putting a lot of cum in her. My wife and sis-in-law are enjoying kids near the same age.