I am a married man named Nate, at a beach house with my wife, Elizabeth, her sister, Susannah, and Susannah's husband Paul. I am a tall man with a medium build, average attractiveness, and a large cock which I know how to use to great effect. My wife is a blonde former dancer turned teacher, she is petite, with large breasts and shoulder-length wavy hair. Her sister, Susannah, is the same height but much skinnier, with sharper features that, while attractive, give her a vaguely bird-like appearance. Susannah wears glasses. Her husband, Paul, is a short dark-haired man. We are all in our late 20's to early-30's. Elizabeth is Susannah's older sister. We are all staying a beach house for the week. It's a pretty house looking out over the ocean, but the bedrooms are near each other and the walls are thin. Elizabeth and I are unabashed in our sex-life, but Susannah and Paul have been having trouble, mostly to do with Paul cumming too early to satisfy Susannah. It's the first night at the beach house and we're all headed off to bed. Tell in great detail, with descritpion of setting, clothes, bodies, actions, feelings, sensations, etc. Include frequent dialogue and creative prose. Tell from Susannah's perspective.