Who first called robin the boy blunder?

The phrase "Robin the Boy Blunder" is not a commonly known or used phrase in any significant literary or historical context. Therefore, it's impossible to say who first called Robin the Boy Blunder.

It's possible that:

* It's a made-up phrase: The phrase could be a recent invention or a nickname used within a specific group or context.

* It's a misremembered phrase: There might be a similar phrase or nickname associated with Robin Hood or another character that has been misremembered or modified.

If you can provide more context about where you encountered this phrase, it may be possible to give a more accurate answer.