This hillbilly tale was posted on the groaners listserv a couple of years ago. I think it is older than that.

Suzie Pearl done fell in love;
She planned to marry Joe.
She was so happy ’bout it all;
She told her Pappy so,

Pappy told her, “Suzie gal,
You’ll have to find another;
I’d just as soon yo’ Ma don’t know,
But Joe is yo’ half-brother!

So Suzie put her Joe aside
And planned to marry Will,
But after telling Pappy this,
He said, “They’s trouble still.

You can’t marry Will, my dear,
And, please, don’t tell yo’ mother,
But Will and Joe and several mo’,
I know is yo’ half-brother.”

But Mama knew and said, “My child,
Just do what makes you happy.
Marry Will, or marry Joe,
You ain’t no kin to Pappy!”