In the cramped, dark confessional, the siblings huddle together, their bodies barely concealed by their thin, worn clothes. She's the older, more worldly, her eyes filled with a hunger she doesn't understand. He's innocent, his cock twitching at her proximity. She reaches out, her fingers brushing against his hardness, feeling it throb under her touch. She whispers her sinful desires, her voice barely audible, yet it ignites a inferno within him. He pushes against her, his cock straining against his pants, seeking release. She unzips him, her hand wrapping around his cock, stroking him until he's panting, his cum spilling onto her waiting fingers, their taboo lust written in the sticky, warm fluids that bind them.