Years ago, three of my co-workers were flying back to Seattle BA Business class after some meetings at Rolls. Pre-flight, one of them (a bit of a hippy type) showed up at the Business class lounge wearing cutoffs and a t-shirt, and BA refused him entrance. He objected that two of his co-workers were already in the lounge and he wanted to join them. BA responded by escorting the two co-workers
out of the lounge
.
It took years for him to live that down...