Hahahaha, I find myself doing it all the time in front of family or friends at work
for example yesterday, we were having a meeting about some new imaging software, and my boss was explaining that the company we were using had made a mistake with the number of liscences or some shit, and without even knowing it I said (rather loudly) "Oh brother! where do these clowns come from" hahahaha they all just looked at me a bit strange
If anybody else is a victim of this, post your stories here!!!