As the sun sets, the siblings huddle in the closet, their breath misting in the dim light. The brother's cock tents his pants, his sister's eyes locked onto it. She reaches out, tracing its length, feeling it pulse. He gasps, his hips bucking slightly. She unzips him, revealing his hard, uncut cock, and takes it in her mouth, tasting the salty pre-cum. He grips her hair, fucking her mouth gently, while she grinds her pussy against his leg, her panties soaked. They're quiet, their moans muffled, but their bodies speak a language of their own, a dance of lust and taboo.