On: The Itsy-Bitsy, Teenie-Weenie, Very Litigious Biki...

[gspleen]

This is strange. I was curious about the meaning of “pretending to be armless John” so I googled it.

There is only result for the use of that phrase:

Your post.

So what's your fun example situation for us of someone “pretending to be armless John”?

https://www.google.com/search?q=%E2%80%9Cpretending+to+be+ar...

[soneca → gspleen]

Act as someone who does not understand a situation in order to not do something or not face the consequences.

An explanation I read is a reference to mutilated men being dismissed from going to war

https://www.dicionariopopular.com/dar-uma-de-joao-sem-braco/

( A Google translator might help)

[reubenmorais → gspleen]

João-sem-braço (literally, John-without-arms) is someone who feigns ignorance, pretends they're not aware of something to avoid doing something unpleasant or for personal gains.

[gota → gspleen]

A reputable publication in Brazil had a columnist write about the origin of the sentence here (obviously in Brazilian Portuguese): https://veja.abril.com.br/blog/augusto-nunes/de-onde-vem-as-...

Apparently, beggars would tie one arm (or both) around their body under clothing, pretending to have been injured in war.