I like the theory that the boyfriend is the milkman.
Guess I'll just list the pieces numerically:
"Not one of them knows the end". The boyfriend is dead, so he can't tell the story...therefore neither can the milkman.
Boyfriend has a drunk temper (significant with the gin later)
The milk is still cold. The boyfriend drops off the milk (yes to his own house) at 9am and finds the preacher at the house. Since it's early in the day it explains why Billy is just waking up in his truck and the milk is still cold.
Too many lines seem to confirm the preacher is his daddy. It doesn't seem to fit that the preacher is not his father.
10 year old walks in with the hat/gin. This is what confirms it for me. You have to picture this scared 10 year old kid in the other room for the whole song. He hears everything go down. After Billy kills him, the innocent younger brother knows they are going to bury the boyfriend. So, he comes into the room with the gin and hat knowing they are the boyfriends articles and must be buried with him.
".....go and ask milkman". I like this. Go and ask a dead man to tell you tale.
I like the theory that the boyfriend is the milkman. Guess I'll just list the pieces numerically:
Just what I think :)