Last summer, I started having sex with a woman I work with. Cindy is a few years older than me and married, but she is extremely hot. She told me her husband no longer satisfied her physically, so I had no problem filling that role. One day, she introduced me to her younger sister, Lisa, who is also hot. She was the only one who knew about our affair. A couple of days later, Lisa emailed me, and I could tell she was coming on to me. We exchanged some flirtatious emails back and forth. A few weeks later, I went over to her house and had sex with her all day. Lisa told me she had no problem with it because Cindy was already married and shouldn't be cheating anyway. She also said Cindy told her about how good I was in bed and how well-endowed I am. I continued to casually date Lisa while occasionally having sex with Cindy for a couple of months, until one afternoon, totally by chance, Cindy caught Lisa and I in a market together. She didn't flip out right away, but the next day she showed up at my house and tried to hit me. I managed to settle her down, but I could tell she was still pretty angry. We went at it like animals, and while we were having sex she screamed out, "Who's better?!" several times. Then she made me say she was the best lay I've ever had. It was intense.