Balderdash: senseless talk or writing; nonsense.

Oxford language definition

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My kid talks balls all day long
His ball themed tales go on and on:

My balls do this, my balls do that
My balls could sucker punch the cat
My balls could bounce to Timbuktu
My balls could fall into the loo
My balls could fly to outer space
My balls look like an old man's face
My balls help me play air guitar
My balls can stretch out really far  

I tune it out, try to ignore it
Tell him off, act bored about it
His ball talk will not be deterred
I fear he may be soon interred 
For the love of God will someone please
tell me how long is puberty?

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Of course, he could mean footballs, or tennis balls, maybe a basketball? Yes, that helps.