Let me start by saying we change our own sheets weekly and of course I would normally change them between guests.
However, an adult DC and their partner have jobs where they travel around a lot. If they are in the area they are welcome to call in and there is always a bed if needed. So, DC stayed on Wednesday night, I haven't had time to strip the bed. Partner has asked to stay tomorrow night. I'm going to leave the same sheets on, they live together, sleep together and really won't care.
My neighbour says she would change the sheets anyway. Please tell me that you wouldn't.