This is my first AIBU so please be kind... ah who am I kidding? do your worst...
This is not really a big problem and has been resolved (from my point of view) but DP thinks I'm being terribly precious.
DP has two younger brothers, one on gap year, one at sixth form, who both live at home with both his parents. They have five or six towels in the bathroom, all exactly the same, which they all share, and DP does too when he stays. We've been together for six years, and until recently I had always been given my own towel (or had one with me). When we stayed for a few days between Christmas and NY, however, none materialised (NO ONE is allowed in the airing cupboard except MIL), and when I asked DP's parents they said 'oh you're one of the family now, you can share ours'. Very sweet of them to say that, and not wanting to be difficult, i did use a towel on that first occasion, but felt a bit funny about sharing towels with five other people (have no prob sharing with DP, but a bit weird about the rest of his (admittedly very nice) family) - and the towels were a few days old and are used as hand-drying towels as well. At home and at my parents' everyone has their own towels.
Later that day i went to the supermarket for his parents, and i put a cheap towel in the trolley and used that for the rest of the stay, took it home with me and washed it myself. I said nothing to his parents, didn't create any more work for anyone else and will always bring my own towel in future. Not a problem - no need to make a fuss about it. Dp says i'm being terribly precious and silly about it and should just get on with using the available towels. Me, I think i've resolved something that was a small problem for me alone very simply and there is no need to make a big deal about it. We haven't had a big argument about it or anything but i do object to being called precious and silly under the circs - so am I?