Very early in my CF career (like 3rd or 4th character, early 2000s) I played an Entropy gnome healer of Pico. Hopefully not chaotic stupid but definitely silly.

I was on an trip, occasionally throwing heals at our enemies and doing things I thought would be chaotic. I was real into the RP, totally in the mindset, in the groove. Anyway, we killed a something and an item dropped and I grabbed it to identify. I see that it is flagged rot_death so I blurt out "Eww, rot_death what's that?" because that's what Zandrumial would say if he saw something labeled "rot_death"

I immediately realized that Zandrumial didn't see that - I did and told my group "forget that, I said nothing." They just chuckled at me and we moved on.

Maybe not the most embarrassing thing ever, but I hadn't broken RP before and not so visibily given that this was the kind of trip that you know a few Imms are watching. I later heroimmed him though so I guess it wasn't so bad.

Ironically it happened in part because I was so into my RP that I forgot to make a distinction and resopond how my character would react to seeing that phrase, but still... embarassing.