Shitting your pants in public or at any public gathering of five people or more and utterly embarrassing ones' self.
Also farting excessively in attempts to "be funny' yet having it backfire on you by accidentally making a mess of your boxers, (most often at Pizza Hut after consuming wild spices. i.e. Cajun or anything with strong flavors.)
You: "Nice dinner right? The wings were great."
Friend: "Oh, crap!"
Friend: "I think I'm gonna Pull A Chunko!"
You: "Thats gross man, you're not sitting in my car. Damn him, Pulling A Chunko like that, *laughs hysterically*"