In the 70's I used to work at a large (400 attorneys) lawfirm. There was a restaurant/bar/club on the 5th floor of our building that only allowed men to be members and/or patrons. I started asking the lawyers getting on the elevator on the 5th floor if they'd been to that "gay" bar for lunch. They'd get a stunned look and say "What?" I'd reply - "Well, they only let men in there, so I figured it was a gay bar." Interestingly enough, a couple of months later they started allowing women to be members and patrons.