Junshin Karen na Amaeta Imouto ni Ochinchin no Osewa wo Yaite Morau Seikatsu! | 純真可憐な甘えた妹におちんちんのお世話を焼いてもらう生活！ ～お兄ちゃんのせーしピュッピュして赤ちゃん作ってください♪～

Related by marriage, a hentai big brother thinks constantly about his new sister. She sees him one day while he's masturbating to fantasies of her. She's too innocent to know what masturbation is and mistakenly believes his penis is hurt. Without a second thought he asks her to help him make the swelling go down. It's the start of a taboo life of doting love and discovery!