As mentioned above, Mary Mack, in full as I know it.

CHORUS: Mary Mack's father’s making Mary Mack marry me.
My father’s making me marry Mary Mack.
I'm gonna marry Mary, so me Mary can take care of me,
And we'll all be feeling merry when I marry Mary Mack.
Dithery oo dn da dn do n da a dithry idle day. (Just for respite!)

Now there's this little lass I know, her name is Mary Mack.
Of all the girls I know, 'tis her I'm going to back.
A lot of other fellas'd like to climb upon her back,
But I think they are very much mistaken. CHORUS

Oh, she's a lovely little lass, and she has a lot of class,
And she has a lot of brass coz her father deals in gas.
I'd be a silly ass if I left the matter pass.
I'm damned if I would ever find one better. CHORUS

The wedding's on a Wednesday now and everything’s arranged.
No sooner have they made their minds up, when their minds are changed.
To think of the arrangements now, I'm nearly disarranged,
For marriage is an awful undertaking. CHORUS

It's sure to be a grand affair, or grander than a fair,
And of course there'll be a coach and pair for every pair that's there.
I'll be on the finest pair. I'll surely get my share.
If I don't then I am very much mistaken. CHORUS

It goes well then, as with all tongue twisters, to sing chorus very rapidly at the end of the song, but for a real laugh, finish, then announce you learnt the chorus backwards, as the audience gasp in astonishment at your talents, simply turn your back on them and repeat the chorus. Never ever fails!