GVH-369 Her sister is a masochist, Miyazaki Rin

"I" was visiting her house today. Me, my girlfriend (college student), and her older sister (OL) start drinking at home in the living room from noon. After a while she fell asleep on the sofa, probably because of her drunkenness. I had no choice but to relax next to her as she was sleeping, and in the dining room across from me, her sister suddenly took off her clothes. Despite my surprise, her older sister tied herself up with hemp rope and showed off her masochistic masochism, and she begged me to train her...