@Eileen119
That would depend if the guest is on a business trip or not.
Click the link for details who-can-book-trips-on-behalf-of-someone-else
For personal travel it should be the person who booked that stay's, Tricky situation, how do you throw them out ? you could let it go and in the review of the guest give them a thumbs down for allowing a 3rd party booking on the account.
I get quite a few 3rd party bookings for granny or aunty and so long as I know I don't mind, I should point out that 3rd party bookings will void airbnbs host insurance, but its rubbish insurance so I have my own.