Where did the phrase on a crack and break your originate?

The phrase "on a crack and break your" is not a common or standard English expression. It's possible you might be misremembering or mishearing a different phrase.

Could you please provide more context or information about where you heard this phrase? Perhaps you can recall:

* The full sentence or context: What was the sentence or situation where you heard this phrase?

* The speaker: Who said it?

* The topic: What was the discussion about?

With more information, I might be able to help you understand the phrase better.