Two devout sisters, Mary and Catherine, struggle with their carnal urges, haunted by religious guilt. One evening, as they pray together, their thoughts turn to the forbidden. They sneak into their parents' room, drawn to the untouched, massive cock they've often fantasized about. With bated breath, they strip, their bodies trembling with anticipation and fear. They take turns riding their father's cock, their tight, virgin pussies stretched wide, as they silently pray for forgiveness amidst their profane ecstasy.