[Sena Youtarou] Perverted Onei-chan Ch. 1-7

An older sister with glasses, a black ponytail, and an insatiable appetite seduces her younger brother, promising they'll never speak of it again as she slides his cock into her wet mouth. The story spirals further into taboo territory when a fox-eared demon girl claims the boy for herself, offering her smartphone as payment, leaving the sister to watch helplessly. As the festival night ends with the boy passed out, the sister creeps in for one last forbidden taste, begging forgiveness in a twisted, emotionally charged finale.