Relatives like to drop in with no notice

DEAR ABBY: Some relatives come once or twice a year from out of state to stay at my in-laws’ house. For the past 20-plus years, it has been the same routine. They show up, but we never know ahead of time when or how long they are staying. We are expected to drop everything to go over there to visit with them as long as they are in town. There are no plans and no schedule; we just sit around waiting for them to decide what they want to do.