Using "ass" as an intensifier is a dangerous thing to do around avid or even occasional readers of XKCD. This is because of the invention of the Munroe Hyphen, used to mock the misappropriation of the buttocks inherent in this linguistic construction.
"Ass", as a hyphenated suffix to a word, is an intensifier, used to add vulgarity and therefore a punchy sort of emphasis to a portion of a phrase. As a hyphenated prefix, however, it has not endured such a definition shift; "ass-" prefixing a noun is literally interpreted as "of or pertaining to the buttocks". Because the compound "adjective-ass" construct is always used as an adjective, it is merely a hyphen placement away from the latter construct.
"My hobby:
Whenever anyone calls something an adjective-ass noun, I mentally move the hyphen one word to the right"
--Randall Munroe, "Hyphen"
This mental exercise will both produce amusement and a tendency to avoid the adjective-ass construct in one's own speech. It highlights, however, that there is a world of difference between a hard-ass test and a hard ass-test, to say nothing of the difference between- to borrow a few softlinks- a big-ass pork plate and a big ass-pork plate.
Psychologically, the Munroe Hyphen bears some resemblance to The Game, as it is nearly impossible to avoid participating once you've heard about it.