Would It Help if You Thought I Was Your Step-sister

(Joe Dirt Parody) I met this smoking hot girl today and invited her out on my boat. She was extremely excited and appreciative for me taking her out because apparently her foster step-parents don't let her leave the house. As we get ready to leave she asks me if I'd want to take her home, and fuck her. I immediately jump on that idea and we head back. On the way there she can't even wait so she has me pull over so she can suck my dick before we even get to her house. Then it all went bad. I asked her more about how she became fostered and I think that she might actually be my step-sister. So I hop out, lock the door, and leave her on the side of the road. A few days later I show up at her house to explain what happened. Apparently both of our stories about how we became orphaned were exactly the same, and so I think she IS ACTUALLY MY STEP-SISTER. She reassures me that there is no chance at all, and we pick up where we left off.