@Katrina14, Here's the exact language in the Terms of Service that @Andrea9 was referring to:
"Overstaying without the Host’s Consent
If you as a Guest stay past the agreed upon checkout time without the Host’s consent, you agree that Airbnb Payments, in its role as limited collection agent for the Host, may charge any Payment Method(s) you have on file to collect, for each 24 hour period that the Guest stays over the agreed period without the Host’s consent, an additional nightly fee of two times the average nightly Accommodation Fee originally paid by the Guest to cover the inconvenience suffered by the Host, plus all applicable Service Fees, Taxes, and any legal expenses incurred by the Host to make the Guest leave (collectively, “Additional Sums”). In addition, Airbnb Payments may recover any costs and expenses it incurs in collecting the Additional Sums by charging the Guest’s Payment Method on file."
This language is in the Payments Terms of Service (Section 9) which the guest agreed to. You can quote it to him. Also, you can tell the guest that while he is paid through the night of the 12th, you'll be happy to inform Airbnb of his overstay and collect 2 times the average nightly fee for the 13th. I'll bet that will get his attention and change his attitude!
