Discovering Erotic Adventures in caught jerking off by sister

Rain lashes the floor-to-ceiling windows in caught jerking off by sister. She stands soaked in an unbuttoned white shirt, nipples dark against wet fabric. In caught jerking off by sister, the shirt drops, and rain-cold skin meets warm palms. She backs against the glass, city lights strobing across her body while her hand disappears between her thighs for caught jerking off by sister. Every thrust of her fingers fogs the window anew. Thunder rolls just as her knees buckle in caught jerking off by sister; lightning flashes on her open mouth mid-orgasm. When the storm quiets, the only sound in caught jerking off by sister is water dripping from her hair and the soft click of her satisfied sigh against the pane.