It’s the deadline to fill out your census form. Have you done yours?

When I tell straight people about my family, I often say, “We’re two couples raising three children together.” If you squint just right, our family bears a passing resemblance to a blended family, except we all live together and no one had to break up for it to form. We live openly as a four-parent family and have supportive relatives, friends, teachers, and child care providers. We are unfailingly kind, polite, and grateful to them—always grateful. It is genuine: we feel thankful when people are nice to us and don’t treat us like freaks. When someone refers to Nic or Mars as my...