I think the original words were definitely "I don't care if I do", which was presumably an older idiom for "I don't mind if I do". I have a recording of it by the McNulty Family. The words they sang are (allowing for possible transcription errors on my part):

You ask me to sing you a bit of a song
It's not very short or it's not very long
You ask me to sing you of something that's new
Well me darlin', says I, I don't care if I do

Me name is Dan Murphy, a farmer am I
I courted a lass and I felt rather shy
She bid me come in for a moment or two
Well me darlin', says I, I don't care if I do

We entered the kitchen, 'twas cozy and bright
A fine hearty supper I put out of sight
Says she "Have a drop of the old mountain dew
"Well me darlin', says I, I don't care if I do

And when I was finished, I picked up my hat
Says Peggy, the darlin', "Don't leave me like that
"She asked me to kiss her like fond lovers do
Well me darlin', says I, I don't care if I do

And now Peggy darlin's my beautiful wife
With fine healthy children to brighten our life
For the rest of the world I don't give a straw
We've a rose-covered cottage in Erin go Bragh

(repeat last verse)


The McNulty's may have altered the lyrics somewhat from their source material - for example, the last verse where they have children, instead of "...no little babies to dance on our knee".

Don