I can't explain why, but I was always attracted to my older sister, who's a little over a year older than me. We hit our teenage years about the same time, so we still lived together when our hormones were out of control. She was always very desirable, and she developed a reputation of being a slut in high school. Let's say I don't like calling women that just because they enjoy sex, but yeah, she gave in gladly to the prospect of experimenting something new in sex. So she was game when, one night our parents were not home and we were drinking in the living room, I started to kiss her and fondle her. She took my virginity and it was the first time she ever felt cum in her pussy.
We're now in our thirties and still lovers, obviously in secret. We just enjoy sex with each other too much to let it go, even if I date other women and she's married. She's actually pregnant, and we have the theory that it's actually mine, not her husbands'. The idea of cumming inside of her and getting her pregnant gets me going so bad.