I went to see Rocky Horror Picture Show and everyone kept getting up and singing!!!
At my theater some people used to get nude too. RIP Rialto Theatre - to add insult to injury it’s a church now. Dr. Frank-N-Furter is rolling in his grave.
And yes, at the time I thought the people were being rude, especially when they where howling at the usherette.
Then I saw other performances online and felt like a complete tool :)