To express surprise and delight at an unexpected happening. (An alternate usage is a long-winded of telling somebody to fuck off.)
Doug: Man I got a blow job from that really hot chick.
Fred: Wow! Scratch my balls!

Alternate usage
Doug: Hey Fred, buy the next round of beers mate.
Fred: Scratch my balls!
by Baba Sarah June 13, 2007
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what to say when either:

A) you have extremely itchy balls!!

B) you want to get people to shut the fuck up

C)there is an unbearably awkward silence
Red: damn its quiet in this bitch

Blue: i got the solution for that. *clears throat* SOMEBODY COME SCRATCH MY BALLS!!!!!!!!!!!!!!!!!!!!!!!!!

Green: WHAT THE FUCK???

Blue: there, silence broken

Red: you are a fucking moron
by zerosai93 June 7, 2009
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