A twisted derivative of the term "Meat sweats". Rather than intense sweating due to the ingestion of high amounts of various meat products, Meatball sweats strictly refers to the uber crazy amounts of perspiration in the area surrounding one's testicles.
Holy Hannah! This volleyball is so intense it give me Meatball Sweats!!
"Dude.. did you wet yourself?"
"Nah bro I got severe meatball sweats."
"Aghh word dude, I love when that happens"