Traditionally, all of the parents sit together at the wedding reception. If there's room, the same table will usually include the wedding officiant, the grandparents, and any siblings that aren't in the wedding party. There are no hard and fast rules, however—it's your reception, so you can arrange it however you like. For groups of parents who don't get along well, divorced couples, or simply sets of parents who might prefer to sit with their honored guests and relatives, it's entirely fine to configure the wedding reception table arrangements differently.