After I paid nearly everything for my sister’s wedding, she stood in front of our relatives and tore my invitation in half. “You’ll only ruin my perfect day,” my parents clapped in agreement. “If she doesn’t want you here,” my father said, “leave.” “So be it,” I answered. I walked out before anyone noticed I was smiling. They still believed every payment, every vendor, and every reservation belonged to my sister. Early the next morning the venue manager called her…