Not a one-nighter, but one of the first hook-ups with this girl:
I was fucking around with my high school girlfriend after school one day in the den of my parents' house. My parents were the kind of "don't have girls in the house when we're not here" kinda folks. Well, we're going at it, butt-naked in the den, when I hear the door at the side of the house open. We both jump up, I run out the front door of the house and into the yard with nothing but a t-shirt on and the biggest boner in the world (it was broad daylight). I run to the side of the house and put my pants on, and reenter the house to find my dad in the kitchen. I'm thinking the coast is clear, but my girlfriend hasn't come out of the bathroom. My dad and I walk into the den talking, and there on the floor are her panties, bra, and shirt. my dad laughed silently as I shamelessly knocked on the door of the bathroom and handed them to her.