@Suzanne18 I have a similar problem, sort of a variation on your theme. I rent an entire home with 2 bedrooms: one with a queen bed the other with 2 twin beds. It's perfect for 2 couples but every now and then I will get all male or all female guests two of which don't want to double up on the queen which is understandable. In my case I have an airbed that I set up to accommodate them and since it is so rare, I don't charge extra for linens, etc. I don't charge by the person. I charge the same regardless of the number up to a maximum of 4. You will have to decide, based on how often this occurs, if you want to rent by the room or by the number of people. So if 2 people want to sleep in two beds, then you have it covered.