https://imcc.dk/core/wp-content/uploads/2019/07/IMCC-1950-2015.pdf

A 1965 Danish medical student songbook in part reprinted in the above PDF has the following:

The Youngest Child
(Mel. Cielito lindo.)

She lay nude between the sheets
And I beside her lay;
And she was soft and round and chubby,
Under my hand uprose her bubby.

My hand beneath her waist did stroke,
Her tip-tops itched and tingled,
I clambered up, began to poke,
And our juices intermingled.

“Pull out! Pull out!” the fair one cried,
“Before I swell with trouble.”I did.
And on her snow white breast
My come did froth and bubble.

I gazed into her frightened eyes
And with a leery curse,
“This is the youngest child,”
I said,“That you will ever nurse.”

She picked it up with one fair hand,
And with a shocked “Oh La!”
She threw the load into my face,
Saying, “Child, go kiss your Pa!”