In front of a girlfriend or especially a wife was cause for a fight.
Woody Guthrie's lyrics to "preety boy Floyd" tell it.
It was in the town of Shawnee,
A Saturday afternoon,
His wife beside him in his wagon
As into town they rode.
There a deputy sheriff approached him
In a manner rather rude,
Vulgar words of anger,
An' his wife she overheard.
Pretty Boy grabbed a log chain,
And the deputy grabbed his gun;
In the fight that followed
He laid that deputy down.
Then in the end he says
Yes, as through this world I've wandered
I've seen lots of funny men;
Some will rob you with a six-gun,
And some with a fountain pen.
And as through your life you travel,
Yes, as through your life you roam,
You won't never see an outlaw
Drive a family from their home.