What should I do when long stay Guests are inviting family over temporally?

[Linda4964]

I am experiencing ongoing issues with principal guests inviting their families over, and it makes me nervous. I have a situation in which the principal guest made a reservation for an extended stay (2 months). He booked as a one-person, however, he is telling me 3 members of his family will come separately, for about a week, and on different dates, during his stay. 

- I gently ask him to add the 3 family members to the reservation, for both his and my liability. I think - please correct me if I'm wrong - that Airbnb requires the principal guest to disclose the extra guests. In my case, I charge a very small additional guest fee for the 3rd guest and beyond.

- Now, if the 3 family members stay only a week each, can I refund the days they weren't present, and how do I do that?

My biggest concern is that, every time a guest hosts unbooked people, we suffer mess and breakages while the guests deny responsibility. Our home is a good size, but I don't want large groups to crowd my home or bother my neighbors.

Thanks

[Marie8425]

@Linda4964 

First correct stance is the Guest requested a 1 person reservation for 2 months that is all you are required to pro vid doesn't matter if you can accommodate more people.  He didn't seek approval from you.

There might be a legitimate reason, but to temporarily need to be somewhere and 3 family members at different dates also need make sure you are comfortable with explanation.

There isn't a shortcut to protect yourself if you don't follo your rules,

The Guest need to cancel the solo reservation,  The Guest then submits 5 corrected requests so you approve an additional guests specified dates.