What’s the quietest thing you’ve ever had to cue?

Last week, I held a silence so long between two cues that the stage manager actually blinked at me like I’d disappeared. Not a sound, not even the hum of the grid—just breath. I didn’t know it was a cue until it wasn’t. Now I keep wondering: what’s the smallest moment you’ve ever had to hold for someone else? And did they even notice?