I was on a conference call at work. One other person on the call I knew and was on my team. The rest of the people, I didn't know who they were. Basically, I was just listening on the call and not participating or anything.
The aforementioned person that I knew was sharing his screen to the whole group on the call (going over a Power Point). The group was discussing the presentation, normal conference call stuff.
Well, this one other guy on the call was going on and on and on and on. Just droning on...rambling basically. The call was starting to drag, big time.
So, in my lapse in judgement, I IMed my coworker (who was sharing his screen) and said "this guy talks too much".
As soon as I hit Enter, I saw it pop up on his screen (presumably for everyone on the call to see). I went into instant panic mode. I turned my head to try to get my coworker's attention, but he had his head facing down (also bored of this guy's rambling, so he had his eyes closed).
I immediately jumped up from my desk, ran over to his desk. Told him what I did, so he stopped sharing the presentation, closed his IM windows, and turned sharing back on.
No one on the call said anything, so I don't know who, if anyone saw it. Or, if they did see it, hopefully they were unaware that I was on the phone, and maybe I was IMing this guy for some other reason.
But I was mortified, and thought for sure I was going to get reprimanded or fired. But no one ever said anything.