Is anyone else wary about sitting into a game with miltiple players from the same city?

2 players at a 6 max from Las Vegas, no big deal.
But like last night on AP, 3 players in a 6 max from Lubbock = no thanks.

I could wait around and look for clues (squeezing, soft play when in hand together) before sitting in, but usually I'll just pass on seats in otherwise decent games.
Think I'm too nervous about this?