And if you're not one of them...
4 seconds sound clip from the Die Hard (1988) movie soundboard.
You can hear this line at 01:33:05 in the Blu-ray version of the movie.
Quote context
[...]
- Well, he might be a cop. I don't know. We're checking on that.
- Yeah.
- You don't work for Nakatomi.
- And if you're not one of them...
- Yeah. Got invited to the Christmas party by mistake. Who knew?
- Yeah. It's better than being caught with your pants down, huh?
[...]