We were nearly an hour in to gig before I spotted them.
Dave understood when I pointed them out, but Ritchie couldn't follow.

Me: I just saw four people without crew passes.
Him: What, you mean they didn't get issued them?
Me: No, they don't need them.
Him: Why not? Everyone should have got a crew pass.
Me: They're not crew.
Him: Well, what are they then?
Me: Punters.
Him: Huh?
Me: Punters. Four of them. No Crew passes.
Him: I don't follow.
Me: There's four Punters here. We have an audience.
Him: ...ohh...

And with that he wandered off to get the second act of the day on stage.