My parents remarried and my new step-sister is super cute! My parents went on a week-long trip together, leaving me alone with my step-sister! ...But then my step-sister's boyfriend came over and we had sex in the house! I was frustrated and excited and couldn't stand it anymore! I thought she'd get angry, but when I touched my step-sister's body next to her boyfriend who was sleeping, she said "keep going" and suppressed her voice and felt so good! My step-sister, who wasn't satisfied with sex with her boyfriend, came so much during sex that she even let me cum inside her!