Choosing a sitter for your cat is something that should be taken very seriously.
One red flag missed, and some of the weirdest situations can happen. We say that because we have seen it. Cat sitters might bail on you at the last moment, without proper warning. Cat sitters might steal from you, and then of course deny it, and you will have no way of knowing for sure. Cat sitters might let your cats outside, unsupervised, putting them at risk, despite the fact that you told them not to do it. Your cat is your family. You have to know who you are leaving it with.
Which is what makes the situation in this story quite… understandable to us. At first, this was a cat sitter that the cat owner trusted. It wasn't the first time that she took care of this person's cat. The trust was there. But the moment that she asked whether a complete stranger could be allowed to crash in the cat's home, that trust was broken. Of course, the whole situation could have been handled with more sensitivity, but the point still stands. This cat sitter knew how important it was for the owner for them to not bring strangers into their home. She knew.
source https://cheezburger.com/43960069/i-was-very-clear-no-guests-in-my-apartment-cat-owner-cancels-cat-sitter-after-she-asked-whether-her