Intrigued what people think on this one.
On holiday abroad somewhere hot and sunny last week. Hotel pool had (not enough) loungers, pool towels were available at the pool and given out as you arrive.
YANBU : if you are vacating your lounger for whatever reason - going for a swim, a walk, the loo, a very long lunch (another issue maybe) then you need to leave something on your lounger as well as the hotel pool towel that says it’s still in use. Your book, your own towel, a pair of sunglasses, your bag, your shoes next to the lounger. Anything.
YABU - leaving the hotel issue towel and nothing else is sufficient to keep your lounger held for your use whilst you’re away from it.
TL:DR I took a lounger (no others obviously available) that had only a hotel towel on it and 2 hours later a cross man turned up and demanded his lounger back - was IBU?