I had this last week, 1 young idiot booked, and then the girlfrind appeared, He aslked lots of stupid questions, about tv, towels, shampoo, etc. but never ever mentioned the girlfriend was coming, was all planned, I let them stay, of course, no extra was offered. Airbnb will not help, they only help guests, now I got another, first booked, my linsting is clearly for one, and specified that is also for Covid reason that I accept only one, He booked and then said is coming with the wife, I called airbnb but they will apply $50 fine if I cancell him, The guest so far do not want to cancel, nor replies to messages, and the cancellation is flexible, very stressful.