Yuko Ono FSDSS-497: Three days of being chased and penetrated by her girlfriend's older sister in a riding position, causing her to ejaculate continuously.

I'm currently living with my girlfriend and we're considering getting married after graduation and starting a job. One day, her older sister, Yuko, came over to visit. After my girlfriend fell asleep, the atmosphere between her and her sister became very pleasant. The next day, after my girlfriend went to her club, her sister came to visit again…