Q. My fiancee wants to invite her child’s godfather to our wedding. Problem is her child’s godfather is also her ex. I can tell it’s the child that keeps them in contact. He’s very close to her, but I’m wondering if it’s really necessary that he come to our wedding. What’s good ex-etiquette? A. As I have said before, good ex-etiquette is based on good behavior after a break-up. The easiest way to ensure that good behavior is to base your decisions on the children involved. (Ex-etiquette for Parents rule No. 1, “Put the children first.”) I hope you plan to include your bonus daughter in your we…