Ever try doing your job while an NFL superstar farts in your face?
That's what happened to the guy testing Antonio Brown's body fat percentage on Monday -- who weathered ass rip after ass rip while trying to administer the test.
Dude must have a nose of steel -- because he was unfazed by the Pittsburgh Steelers' WR's overactive butthole.
In the end, the test showed Brown has 3% body fat -- which the fart-enduring administrator described as "pretty f**king good."
As for Antonio, he chalked up his gas problems to having too much fiber in his diet.