As the water cascades down their naked bodies, the siblings' inhibitions wash away. The sister, her hair darkened by the water, leans in to taste her brother's cock, taking it deep into her mouth. He responds by gripping her ass, pulling her closer as he teases her clit with his fingers. Their breath comes in ragged gasps as they push each other closer to the edge. The sister's orgasm crashes over her like a wave, her body convulsing as her brother continues to finger her, prolonging her ecstasy. They collapse against each other, their bodies slick with water and sweat, their hearts pounding with the thrill of their taboo encounter.