my exercise class fills up 45 mins before the start time, and there is often a "milling around" situation when someone's "spot' has been taken when folks arrive 20 mins later. So far, no verbal protests have been voiced, but I am mentally prepared. I am going to smile (disarmingly) and reply "Its amazing how quickly the class fills up now that the seasonal folks have returned, I got here at 7.0am to make sure I could get in"... then stand my ground. .... with a smile...