My sister always bullies me. While she was cleaning the bath, I got an erection seeing her plump ass and miniskirt panty shot. Noticing this, she secretly started masturbating with inner turmoil and sexual desire. After our mother left, just the two of us alone, we started showing each other masturbation and couldn't control our sexual desires anymore. Even though we're siblings, the thrill of doing something forbidden doubled our excitement, and we ended up having sex.
