The first girlfriend I ever had was a classmate from university. We haven't had sex yet. Her younger sister, Erika, is taking exams next year, so as someone good at math, I ended up tutoring her. 'I get paid for the part-time job and can go to my girlfriend's house—what luck,' I thought casually. But Erika teased me for being a virgin and tried to seduce me by showing off her breasts…
