Hi @Marikathryn0
hope you are well and please do so.
In not doing so this person is allowed to potentially do the same to other hosts and we need fair warning.
I would put something along the lines of
“This booking was originally for x people but up 14 people stayed throughout it, this was communicated to me after their departure. Given this and other aspects to their stay I would find it very hard to recommend them to any future hosts on this platform and suggest they use only commercial hotels. Thank you”
most hosts would get the gist of this- and it does not give them much room to dispute.
I really do wish you luck and hope you have a great day!
Yadira 🙂