"there was an old man
and he had an old sow ...
...non-verbal noises "

Would you believe, an improvised quote
from Marlon Brando, of all people,
in Last Tango in Paris?

I think it might be the scene
with the dead rat.

Which of course is adorned later with
"Rat's - ******** with mayonnaise!"

That's the only place I've encountered it.
I don't get out near enough.