I'm hoping you can help me. We've had a booking through Airbnb today and I'm a little concerned about the booking as two guys checked in, not the woman who booked, and now I can't get hold of her.
IMO you should ask the current guests for an explanation. And if it is a 3rd party booking, then the booker violated Airbnb Terms of Service and you can act accordingly (ask the booker and/or Airbnb to cancel the reservation).