What Grace says isn't untrue, I did peer through the glass in the door after no one seemed to be answering - the venue is exposed, in a crappy area, and there is no door number so I thought I might have the wrong house. When a bloke answered, this was still my thought. When he tried to get me to go in, I decided not to chance it, with no sign of a lady anywhere to be seen. Also, I didn't hear what he said as I left after saying I wasn't coming in, it may well have been "have a lovely day" but he didn't look very cheerful.
It seems likely that I was being over cautious on this occasion, but I have never ever had a man open the door before and this plus the location was enough to decide not to risk it. Maybe I missed out. I shall leave the matter there.