Its Reputation Precedes It

The other day I was messing around with W., and I called him a son-of-a-gun. It's something my dad used to call me when I was around that age (5), and until this moment it had never dawned on me to wonder where that particular phrase comes from. I remember a country song that says, "My daddy was a pistol, and I'm a son-of-a-gun," but I'm pretty confident the phrase precedes that. In any case, W. adamantly denied that he was a son-of-a-gun, but then he suddenly and fluidly shifted gears. "Speaking of guns," he said, "I want to go to Texas."