My tutor, Mina-sensei is my father's mistress! My mother was taking a tea ceremony class every Saturday, and my father took this opportunity to ask Mina-sensei to come and be my tutor, so that the two of us could fuck each other more secretly! And from then on, every time she came to teach me lessons, Mina-sensei would make an excuse to go out and fuck my dad! Because it happened so many times, I was suspicious and followed sensei, so I witnessed the scene of them fucking each other. Not only that, but my dad would cum all over her pussy every time. So much sensei will definitely get pregnant! And during a peek at the two of them, Mina-sensei also spotted me, but not only did she not stop, but she also deliberately moaned louder. After that, Mina-sensei offered me a handjob so that I could keep this a secret. I agreed, and the affair between the tutor and my father continued. But in the end, I couldn't take it any longer! I want to fuck this charming beautiful tutor too! Waiting for my dad to get tired of fucking and going to bed, I went to ask Mina-sensei for permission to fuck her, Mina-sensei agreed, but with one condition, I had to be at the top of my class in the next exam...