Years ago, my visiting sister and I were teasing each other about one of those random topics siblings joke about. My roommate overheard us as she climbed the stairs in our apartment and gently admonished us:
“Now girls, don’t fight.”
My sister and I turned to each other with the same puzzled expression. We weren’t fighting. We were joking around, having a good time. What was she talking about?
I considered my roommate’s perspective: she saw two sisters in conversation with...