Sorry this ended up longer than I expected!
I was at an interactive museum today with my son and his friend. They really wanted to experience one exhibit that a little girl was on - it involved a large screen with touch points that took you through the entire human body. It was quite detailed so lots to see but could only be used by one person at a time. The waited patiently for a good while- 10 mins initially. They then decided to go to another screen close by and returned about 3/4 mins later and again waited. All in all we waited approx 20 mins. It was clear we were waiting for that particular one as it was in a little room of its own and we waited at the door. Eventually I asked the dad is they would be much longer to which he replied yes most likely. I asked if there was any way we could have a turn for a few minutes. He said no as she had autism and wanted to stay on it. He then said I could say it to her if I wanted but that he wouldn't be forcing her to move.
I told him I wouldn't not be saying it to her as she was not my child nor was I asking him to force her but maybe he could have a conversation with her. I'll admit my back was up by this point, not because of what he said but how he said it. He was so rude and dismissive. (the above is not the entirety of the conversation but the main jist of it.)
He then told me he was going to speak to management about me and walked off. We left the area then as waiting any longer was futile. Shortly afterwards I saw him re-enter the area (I have no idea if he spoke to staff). I approached him and said that had he acknowledged our presence, that he was aware we were waiting and explained that they might be there a while we could have moved on. He said we should have done so anyway as his child was entitled to spend as long as she wished on the exhibit. I told him consideration for others (from him) was not too much to ask.
Was I out of line here? I'm very aware that he angered me a lot with his attitude and the dismissive way he spoke to me that I may not be clearly seeing the situation.
Thanks!