I agreed to feed my neighbours cat last year when they went away, and I have to say, never again.
I did ask them to keep her indoors for the week, but they said they didn't want to upset her routine by keeping her in.
The first 2 days were fine, but the 3rd morning she didn't turn up (she's in during the day and out at night
), so I left her food outside as I had to go to work. She didn't turn up in the evening either, so I was really worried. She had been about as someone else had seen her, but the fact that she hadn't actually come home was too much for me to bear. She sauntered in the next day without a care in the world, little minx.
They asked me again a few months ago, but I said that unless they would keep both of them in (there's 2 now), I didn't want to do it as it was such a worry.