Hot As Balls

Where the hell did this phrase come from, and why do I continue to use it even though its origins are unknown to me.

"It's hot as baaaaaawwwwllls, y'all."

My diction, my euphemisms, my phrasing, even my accent has changed over my 28 years as I've moved from place to place...For example when I lived in Chicago I tended to use the phrase "schlep" as in "I'm gonna schlep over to the Jewel and get some raw cookie dough to eat with my wine." I also started using the phrase "pop" instead of soda.

One persnickity thing I refused to use was the queer Midwestern way of not finishing a sentence. Instead of "I'm going to the Jewel to get some raw cookie dough to eat with my wine, do you want to come with me?" they would say, "I'm going to the Jewel to get some raw cookie dough to eat with my wine, do you want to come with?"

Yes..."Do you want to come with?"

Totally ridiculous.

Now I say y'all and hot as balls...hot as a crotch, that's a good one...don't know if that's regional though.