The son discovered his father was having an affair with his tutor.

The tutor, Mina-sensei, is my father's mistress. While teaching, I secretly went to see my father and did vaginal cum SEX. While I was peeping at them. I met my teacher! What. Grinning and freely showing off raw SEX photos! I couldn't hold back my erection in front of Mina-sensei! While I was attending class while being excited, I was tempted to pull me out with a dirty handjob! I promised to pretend that I didn't know about my relationship with my father.