In the monotonous routine of commuting only between home and school, one day after my sister's friends stayed over, I watched her shower through the glass! Huh!? Could it be… she's masturbating with the showerhead!? HUNT-850

My sisters and friends who were staying at my house came to the undressing area to spy on them showering... but the glass was even more transparent than I imagined! I could see their nipples and pubic hair! And they were masturbating! I couldn't stand it anymore and opened the bathroom door. They rushed towards me to shut me up!