Dear Prudence,
My husband and I do not have primary custody of his elementary school–aged son. This is our year for Christmas. (We’ve been on this schedule for three years now.) We were planning on having Christmas with his family at our house this year. However, this weekend his brother asked us which day we’d like to celebrate Christmas. Apparently he and his kids are going to the new girlfriend’s family on Christmas Day. How annoyed can I be about this, and how do I make sure that in the future she doesn’t take over the holidays again?
—In-Laws and the Holidays