Cumming twice on my sister’s innocent face

A 20-year-old sister asks me to help her with homework, and in exchange, she will allow me to cum on her face. The naughty sister, wearing glasses, obediently kneels down facing my dick while I masturbate it. Her innocent face makes me cum on her glasses, but my dick isn’t satisfied. Her hands on my balls and her cute face with glasses makes me cover her face with my thick cum twice.