The encounter was in a park in the middle of the night. On my way home from a convenience store, I was accosted by her in a nearby park. Then we drank together and joked around with each other... Before I knew it, she was at my house. I don't know their names, and I don't know what they do. But for some reason, I couldn't leave it alone ... A record of a few days of having sex with my sister who rolled into my house.