While my wife was away on a business trip, I let my mother stay at our house because she had just had minor heart surgery, and I did not want her to be alone. I thought it would be fine to let my mother stay in the master bedroom because there is a TV in the room and she would have easy access to the master bath.
Upon my wife's return she was angry with me because I let my mother spend one night in the master bedroom and use the master bath. She felt my mother should have stayed in one of our daughter's rooms.
My wife and I sleep in separate rooms because I snore. I don't know what etiquette says is appropriate. This was a unique circumstance. Was I wrong to let my mother sleep in the master bedroom?
Blame it on the Y chromosome
Dear Blame it on the Y chromosome,
You were being very accommodating to your mom due to health reasons.
Where guests sleep is up to the host. However, many people are not comfortable having guests sleep in their master bedroom due to privacy matters. Although your wife sleeps in a separate room, she still views the master bedroom as your and her personal room.
It could be that your wife was not consulted about the matter and perhaps that is what is most upsetting.
Having a guest stay in a child's room is fine; and the child could sleep on the couch. Kids think that it is fun to sleep on the couch and watch TV.
If you do not have a guest room, then the least disruptive place for a guest is the couch.
Hopefully, you and your wife have discussed and worked out where guests will sleep in the future.