Update: All is good, never heard from him yesterday and today.
What I'm worried about: They will leave on May 22 at 6 AM as I mentioned earlier. Now I've provided 6 additional towels on day 1. When I'm there receiving the keys I want to check everything is in place, specially the towels.
I'm thinking to go like "hey, were the towels enough?" and then start looking for them.
I also have brand new glasses, cups, forks, knives, a hair dryer, the iron.
So how would you go about checking all these are there and they didn't attempt to siphon off something to make up for the 1 additional night they paid?