I had a call I had to be on that was primarily listen-only for me, from a very busy common area of a major domestic SkyClub. One of my colleauges on the other end of the call just couldn't understand why I wasn't answering a particularly thorny HR-related question about one of my direct reports, and was thus questioning my judgement. I'm like "man, I am sitting in a room full of strangers and while none of them care, can this NOT wait until tomorrow?"
When I feel badly is when I have to talk to some of my analysts and there is just no vacant place and I've already passed security. That happened to me in the Admirals Club in AUS a few weeks ago, as I forgot that the BA flight was leaving an hour later and thus the club was as jam-packed as all the gatehouses. Nothing confidential, it's just that nobody around me needs to hear about the size of the GIS shape buffer around the lat/long of the truck stops on I-40.