A pants blaster is a fart
so explosive it blows your pants
off, leaving only the waistband.
Often encountered after a taco and beer binge.
Fred's friends heard a gigantic
fart and then saw him staggering down the stairs covered in poop
, wearing only the waistband of his jeans.
"Pants blaster," said Syd.
"Open a window," said Geoff.