My dad remarried with a single mother and suddenly I had a sister. I wasn't even used to living with the four of us yet, but my parents went on their honeymoon, so I ended up living alone with my step-sister. I have to study for my exams, but I can't stop thinking about my half-Japanese step-sister's big ass! I got turned on by her big ass spilling out of her denim shorts, and couldn't resist cumming inside her right away! I thought I could just go ahead and do it, but she refused, so I begged her to finish me off with her mouth. My step-sister's blowjob technique was so good that when I came in her mouth, she swallowed it right away. She drank my semen, which made me even more excited, and my erection wouldn't go down. For a few days while my parents were away, I neglected my exam preparations and let my step-sister suck me off, swallowing my cum over and over again!