(Explanations in italics for the uninitiated.)
$linguist1: "I always like to say 'let's haul' instead of 'let's go'."
$linguist2: "How funny! I've never heard that before. For me, it has to be 'let's haul ass'."
$linguist3: "Yeah, if I said 'let's haul', there'd be a silent 'ass' tacked on in my mind."
$other_linguists: :: giggle :: (Note: Linguists sometimes posit that people don't pronounce all the words if the expression is completely recoverable from just the beginning parts. Thus, in this case, "haul ass" would presumably be recoverable from just pronouncing "haul". )
$linguist4: "Me, too. Our dialect of English is obviously ass-dropping."
$linguist3: "It's the ass-dropping parameter of English!"
$other_linguists: Yeeeesss! :: uproarious laughter :: (Note: Linguists sometimes debate over the parameters of language structure, and a famous one is the "pro-drop" parameter. The "ass-dropping" parameter is a parody of this.)