DEAR MISS MANNERS: We are the proud parents of two adult children, a gay 32-year-old son and a straight 27-year-old daughter.
My husband's oldest brother and his wife (who are our son's godparents) are politically and religiously conservative. The sister-in-law posts many opinions on Facebook about how same-sex marriage is ruining America, causing Christians to be persecuted, etc., although she is always friendly to our son in person.
If our son were getting married, we would invite them to the wedding, and if they refused to come, we would not later invite them to our daughter's wedding.
However, our daughter is engaged first. If we invite them to her wedding, I'm sure they will come. Is there any way to politely say, "We hope you will join us, but we respectfully ask you not to come if you would not attend X's possible future wedding, as we love our children equally"?
GENTLE READER: Despite their stance, your brother-in-law and his wife are not violating any etiquette rules. If they are being polite to your son, then you cannot be rude in return (although Miss Manners recommends that your family stay off their Facebook page).
A current invitation's validity cannot be dependent on the possible outcome of an imaginary future one. And no one is measuring how much you love your children. Invite your in-laws to your daughter's wedding and turn a blind eye if they decline a future invitation to your son's. But given your relatives' proclivity for spreading their opinions behind your family's back, wouldn't it really be better for everyone if they did?