Hi Digby,
I am sorry you experienced this. After reading this I feel it might make a difference to you or other people how I handled it with my girlfriend visiting the EC for the first time.
We went unannounced and I told my gf that if at any point she felt uncomfortable, we would leave. I told her there is no pressure as the entrance is free for couples, and we would go shopping after anyway.
Fastforward to the moment we entered the EC.. there were guys on the couch touching themselves (perfectly fine. It's an erotic cinema, dah). I just mention this as my gf did not expect to see this the moment we stepped inside. We went on a tour of the EC while she clung to me, but we were gone in 4 minutes because I felt her body language.. and also she said I feel like they eye me as a piece of meat (I actually like being viewed like that X"DD).
We had fantastic sex that evening as she experienced something scary, but it was handled safely and that is what she remembers.
It took a few months, but she asked if we could visit again. We have not yet, but when we do it will be on a Wednesday or Thursday evening after 19:00 when the cinema might be empty or really few people. That way she can sit and touch and inspect and look at everything without people following. I really remember how just being able to put my penis through the glory hole without anyway being there already was so satisfying because I never experienced something like that. Or the giggling feeling when I lay in the swing with no one around to even touch me but it was great because I was getting to know everything and how it felt on my own without any pressure.
Anyway, after writing this I am slowly realizing this wall of text might also have been a bit to get this experience off my chest. I hope something in there also helps you in anyway.
Hit me up if you want to talk, doesn't have to be erotic.