In texas hold em poker terms it means pocket Kings (2 kings). A
king (any suit) is often called a
cowboy and as we all know in the movie "Broke Back Mountain"
two cowboys were together hence the poker name for pocket kings or two cowboys together.
If someone has a pocket ace and
king its called a "
Cowboy with a
Bullet". If you have pocket or 2 kings, a better hand, then you would have "Broke Back Mountain".