@Ania1848
You have an exquisite house and I would be outraged in your situation.
In effect the guest has sublet your property to unknown parties without your permission. This is absolutely unacceptable.
I’m not sure if there are still unauthorized people in there or not, but if there are you need to get rid of them immediately. They have no right to be there. They are trespassing. You can get the police involved if necessary.
I’m guessing that this happened last weekend though, so I guess they left without incident.
Were there significant damages? Things missing?
If not you need to decide if you will ever trust this guest again. I imagine that the pool of guests who can afford your place is rather small, so you might not want to embarrass someone who could be a repeat customer.
If there were no damages I would probably wait until the guest posts a review before I posted mine.
If they gave me a bad review I would savage them.
If they gave me 5 stars I would probably give them 4 and add some innocuous remark such as, “I recommend that future hosts make sure this guest is fully informed regarding their policies on additional unauthorized overnight guests and notification in case of early checkout.”
Then I would calmly and politely inform the guest PRIVATELY that what they did was unacceptable and although no actual harm was done, if the “fishing buddy” had trashed the place they would have been fully liable.
If the guest doesn’t post a review before the 14-day deadline, I wouldn’t post my review until the very last minute: 13 days, 23 hours, and 59 minutes.
Have your well-considered review ready but do not click send until you are sure that they don’t have time to backstab you.
You could inform Airbnb of the guest’s inappropriate behavior but I doubt that they would do anything about it.