In the dim light of the candle, the siblings huddle close, their bodies barely covered in thin nightgowns and pajamas. The spirit of the season fills them with warmth, but it's not the Christmas cheer they feel. It's the heat of their bodies pressed together, the friction of their legs entwined. She can feel his hardness against her thigh, he can smell her arousal. They try to resist, but the pull is too strong. They give in, their bodies moving in rhythm, their moans filling the silent night.