Ok, let's say player A is playing James Michael Stern, a railroad baron who secretly dons a suit of steam-driven power armor to clean up the mean streets of London as Ironclad. Player B is playing Julianna Graves, Stern's secretary. They have a scene that's just about the relationships between their characters. No dice or other mechanics are invoked in this scene, it's just a character bit. Player Z watches and, when it's over, makes some judgment calls, and mechanical changes re: the relationship are made to the character sheets based on Z's decision. Maybe he picks options from a menu, or he just says to add 1 to such-and-such, I dunno.
Ever seen anything like this? Where? How'd it work out for you?