Even though she's right next to me, my liberal arts sister seduces her big breasts by holding her in close contact with her whispers dirty talk slut

As a university student, I was invited to my girlfriend's house for the first time in my life and introduced my younger sister, Eimi. Eimi-chan looks plain and serious at first glance, but she seems shy and reads books and seems to have few words. She was waiting for me to serve her homemade dishes, and as soon as Eimi appeared, her body was in close contact with me, whispering in my ear, "Have you ever had sex?" and slipped my hand into my crotch. Then, as if toying with me, I smiled and kept saying obscene words, and began to show off my lewd nature...