Since I was little, my sister has been overly protective of me like I'm her own son. She strongly dislikes it when I try to get a girlfriend or watch erotic books and AVs. When I couldn't hold back my sexual desires anymore and bought some extremely H underwear for my sister to wear, she reluctantly put it on but was too embarrassed. It was so erotic that I involuntarily got an erection. My sister noticed the bulge in my crotch and stared at it drooling, so I jokingly said, 'Want to lick it?' She suddenly took my dick all the way down her throat, so I let her do as she pleased.
