What's a Pie Hole?

Has anyone really ever had to think about this question?

It's too early for this. I'm eating my hopefully GMO free, organic panda bear peanut butter puffs cereal in very vanilla soymilk. It is BC. Before Coffee. Humanling is watching Spongebob before we head out to see our chiropractor/naturopath. Then I hear in a Squidwardian voice from the tv "Will you shut your PIE HOLE?!"

Humanling tosses over to me: "What's a pie hole?"

(Note: I am really glad it wasn't Beavis and Butthead referring to the other food hole, the infamous and probably very genetically modified, Corn Hole.)

Without the timer buzzing out, I think I safely answered.

"It's a mouth."

End of questions. End of story.

The Online Slang Dictionary seems to have my back on this one.

(http://onlineslangdictionary.com) And I picked up a new bad habit that I will probably think in my head since I am trying to squash out any negative or judgmental thinking about anyone. In my early 20s, I would have loved to walk around at the beach casting out "That guy's got quite a pack of franks". Contrary to it sounding like a genital experiment gone horribly wrong, or in the wide world of porn, possibly very well, it actually just means back of the neck fat.

I've learned enough slang for this small era. Time to get my massage from Dr. Kineseology.