Sorry, very boring!
Is Person A unreasonable or Person B?
Person A viewpoint:
I got back from my bike ride and went up to the work showers. I put my stuff down / hung my towel up etc. then had to pop back to my desk for something. Whilst I was there someone asked me something so it was 5 - 10 minutes before I got back to the showers. When I got there, someone had gone in with all my stuff in there so I had to wait until they finished. When they got out, I pointed out all my stuff was there and had a little bit of a (polite) moan. They said "oh sorry, I waited 5 minutes but I thought you were still out exercising and had just left your bits here after getting changed". Surely it's obvious I had just popped away and the shower room was 'in use'?
Person B viewpoint:
I got back from my run and went to the work shower. Someone's bag / towel was in there but I wasn't sure where they were. I waited for 5 minutes or so in case they came back. Most of us get changed and leave our bags at reception but I know occasionally some people leave them in the shower room so I presumed they were out running or whatever. We are a big-ish office (2 floors) so I couldn't go round asking & the other shower was full. I used the shower and was pretty quick, but when I got out the person was waiting. I apologised and explained but they were a bit stroppy. Surely you don't leave your stuff and walk off if you want to use the shower?
First world problems I know!