I just got back from a weekend break with my family (8 of us in all) and we stayed in a large house with a hot tub in the garden.
My sister and I (both early 20s) were in the hot tub sunday afternoon and the owner came in through the garden and told us he was coming to do the chemical check for the hot tub, we were in our cozzies so naturally felt a little uncomfortable that this man we had never seen before had just arrived and came and did that. We asked him if he needed us to get out and he said no so we just sat in the hot tub not knowing what to say whilst he did it. The rest of our family was out sightseeing whilst all this was happening. He was quite unfriendly and blunt with us and the whole encounter was a bit awkward.
We told our family when they got back and they were annoyed on our behalf saying that he should have come back later once he'd seen we were in it, or asked if it was okay for him to do the test. All in all it felt rather invasive.
I get that it's his house and he can do whatever he likes but to me when you're paying someone to stay in their house, surely there should still be some sort of boundaries? Luckily it didn't ruin the weekend but it has left me wondering about what is morally acceptable in situations like these