@Perla139 As @Helen3 mentioned; if you are booking a place that sleeps 10 and it's those ten guests that will be in attendance then it won't be an issue. However if you book a place for 2 or even 4 the they have a backyard with a grill, you will definitely want to run it by the host.
Many hosts today have cameras to monitor for over occupancy and parties to keep their property safe as well as not anger the surrounding neighbors. If you didn't mention it and they do see more than is on the reservation it could go sideways quickly.
Thank you for being a standup guest and wanting to be honest with your host. 😍
Karen