My girlfriend, who I live with, suspects me of cheating and has me fitted with a chastity belt. One day, her older sister, Rin, comes to live with us for a week because she can't sleep due to construction noise... I happened to see Rin after a bath and got an erection without thinking! My sister, Rin, found out about my chastity belt. She played with my chastity belt for fun... and that's how my devilish older sister Rin's one-week titty fuck ejaculation management began! "Please lend me your breasts, big sister. I can't hold it in anymore!"