Every year I look after pet cat for a week or so while relative 1 goes on holiday. Relative 1 never asks me themself (we don't have each others contact details), it's all done via relative 2 and I collect cat from relative 2. Relative 1 never provides food or cat litter so I buy this myself.
At the end of relative 1's holiday, I return cat to them via relative 2. I've never had thanks passed on to me or had a thank you card - even a scribbled note on a postcard. When people looked after my pets in the past I always bought them a small gift as a token of appreciation, but have never received anything from relative 1 - not even a thank you text.
AIBU to feel a bit resentful that relative 1 is saving over £100 on cattery fees but can't even send a few sachets of cat food/some cat litter or even be bothered to say thank you?