My eldest son and partner visit about every month or so to ‘help’ me (that’s another story!) or as a stop off on a long journeys, often for one night but sometimes two. On there recommendation I purchased a new bed, mattress, duvet, pillows etc for them a couple of years ago. Recently my son questioned me in a very challenging way about how frequently I change their bedding. I explained I do it after they have slept over for around 10 days in all but air the bedding in between; he was obviously not happy and expects it to be more frequent. I’m in my 70’s and they are in their 40’s, while I wouldn’t expect guests (as opposed to family) to do it I don’t see why they can’t change the bedding themselves. Am I being unreasonable?