Every week, we lob your etiquette questions at celebrities…and let the answers fall where they may. But every now and again, we bring in celebrities of etiquette. That’d be Lizzie Post and Daniel Post-Senning – the great-great-grandkids of Emily Post herself, and co-authors of Emily Post’s Etiquette: 18th edition. They also help run the Emily Post Institute in Vermont. This time, they tackle door jams, and outgoing underwear.