[LeBoeuf is spanking Mattie]
Mattie Ross: Are you gonna let him do this?
Rooster Cogburn: I don't believe I will. Drop that switch, LaBoeuf. Put it down, I said. You're enjoying it too much.
LaBoeuf: You'll find I go ahead with what I start.
Rooster Cogburn: [Rooster draws and cocks his pistol] You do and it'll be the biggest mistake YOU ever made, you Texas brush-popper!