Young college girl painful sex with maths teacher

Due to this girl being weak in Maths, her Maths teacher asks her to take extra classes. The girl then joins the extra classes of the same teacher. After a month or two, the girl's Maths teacher stops her after the class and asks about the fees. Then the girl, while caressing the teacher's pants, i.e. his penis, says in a sexy way, "Sir, should I change my payment system?" The teacher understood her and nodding yes, took her to the bedroom. Then he fucked her inside so painfully that the girl kept moaning with her eyes closed in pain. Now the teacher used to fuck her two-three times a week in exchange for her fees.