As a college student, I was invited to my girlfriend's house for the first time in my life and was introduced to her younger sister Eimi. At first glance, Eimi seems to be plain and serious, but she seems shy and reads her books intently and doesn't say much. My girlfriend told me she was going to serve me some home-cooked food, so I was looking forward to it, when Eimi suddenly appeared and pressed our bodies against each other, whispering in my ear, ``Have you ever had sex?'' and touching her crotch. sliding her hand on