That would have bothered me more than Mr Spoo, he always likes the thought of someone watching us.
We haven't noticed that happening too much at the club we go to except maybe for the single men. They tend to hang around in the group room area (which we've never seen much going on there) and then when couples or a threesome head into a private room they try to follow or hover around the door till you close it hoping that you won't.
I think there are some couples who come to just enjoy the atmosphere at a club and catch a glimpse of any activities that may occur in other areas of the club beside the designated rooms. We've never been aware of it becoming a problem or issue like you experienced though. It seems to depend on the crowd on any given night. We have a club that we go to most of the time and know a lot of people there (regulars so to speak) but the atmosphere and mix has been different everytime.
Mrs Spoomonkey