My dad remarried after my mom passed away, and suddenly I got a sister. We were still getting used to living together as four people when our parents went on their honeymoon, leaving me alone with my half-sister. I had exams coming up so I needed to focus on studying, but her big ass kept distracting me! I couldn't help but get turned on by how her jeans showed off her huge ass, and before I knew it we were having sex. She refused to let me cum inside her, so I begged her to suck me off instead. Her blowjob skills felt too good that I came in her mouth without even trying. When she swallowed my cum, she offered to take more in her pussy. Without any hesitation, I fucked her until I was ready to cum again. While my parents were gone, I spent days enjoying myself with my new step-sister, taking turns giving each other blowjobs and letting her drink all my cum.