My wife, sister-in-law, and I took a road trip. We grew tired and found a motel to sleep for the night; one room, one bed. We each took a shower and crashed for the night. My sister-in-law slept in between us both. I woke up during the night to use the bathroom and when I got back in bed, she had slipped off her panties. We had sex quietly so as not to wake my wife. I had the best night’s sleep after that. We never mentioned or spoke about that night, and it has been twenty-five years since it happened.