Likening the events or impending doom of a day to that of having an itchy butthole which is the uneasy feeling or "itchy feeling" a person may experience during post-defecation that occurs around the posterior aperture of the alimentary canal also known as your butthole. An itchy butthole day occurs when post awakening, things start going terribly wrong and make you feel like you have an actual flaming asshole, but in actuality, the world is just fucking you in the ass causing a similar, searing sensation in your soul.
I got up late and the kids missed the bus, I spilled my coffee when I got out of my car at work and once I got there I got verbally donkey punched by my boss and I could just tell it was going to be an Itchy Butthole Day.
The act of slamming one's head into someone's nuts while yelling "Oh my GOD, why are you smacking your nuts into my head, man?" This is done while someone is awake but otherwise occupied doing something and is not aware that you are approaching for the meat packing.
Established in Farmington Hills, MI, hence the moniker "Michigan Meatpacker."
I was laying on the couch studying for my econ test when Matt slammed his head right into my nutsack screaming "Christ on a side Car, Sam! Why are you violating my forehead with your balls, you ass wodge?" "WTF?!? You're the one giving me the Michigan Meatpacker, you douche bag!"
The act of slapping one's nuts against another person's forehead while they are unaware of the attack, and then yelling "Oh my GOD! Why are you cracking me in the nuts with your head you ass clown!?!?"
Sam saw Matthew napping on the couch and stealthily approached with his balls dangling free style. He quietly poised himself over his friend and rammed his nuts into his buddy's head screaming "What the FUCK you nut job? Why are you slamming your head into my ball sack?" His friend yelps out "What the fuck is wrong with you, limp dick? You're the one giving me the Kentucky Clam Slapper!"