[DODOMESU3SEI] Ki no yoi o Ane-san ni Iroiro Misete Morau Hanashi

A young boy who never forgot the shock of learning that girls poop too gets the ultimate show when a cheerful older sister agrees to bare it all for him in the woods. Squatting with her dress hiked up, she unleashes a long-held torrent of pee across the ground before straining out thick, coiling logs, her swollen butthole stretching in full view while he watches with heart-pounding awe. She waves goodbye with a promise to come back when he's older—and he swears to himself that next time, he'll be right beneath her.