I've been thinking about my lunchtime sessions with work colleagues of late and also reflecting on the Traveller Adventure write ups I do every other month.
Readers of the latter might have noticed that they're not just retelling the story but include some of my comments or reflections on refereeing the game or other 'meta' comments about players etc.
I find that I'm very tempted in the f2f lunchtime games to sometimes make such comments to the players and either explain why something is (out of game) or admit that 'that bit was invented on the fly' or 'I thought this was really cool' or asking the players directly what kind of approach they want next (serious, light hearted) or something.
In other words breaking the fourth wall.