Here's a not-so-uncommon predicament: A divorced man with kids marries a woman who also has children. At the wedding, their respective constellations of relatives — siblings, parents — get to know one another. Over the years, they start to bond as an extended family. Homes are shared for weekend and holiday visits. Gifts are exchanged, relationships forged.
Then the couple splits.
Suddenly these step-relatives, unbound by biological or legal ties, are former step-relatives, left to puzzle over the sorts of questions that can require a whiteboard to explain.