The brother's thick, veined cock stands at attention, aching for his sister's touch. She tentatively reaches out, wrapping her small hand around his length, feeling his heat. He groans, his hips bucking forward. She licks her lips, her eyes dark with lust, and takes him into her mouth. He grips her hair, guiding her head as she sucks him, her other hand working her clit. Their bodies press together, their moans filling the room as they give in to their forbidden cravings.