What is Slap Your Plastic?
1.
To use a credit card impulsively for a purchase. If you have no credit card, then a debit card will do as well. If you are not broke.
--
Bud: Dude, harsh, this is total grindage, I got no
shrapnel to pay for this chili dog and slurpee man!
Doyle: Woah bro, no worries!! Chill about the chili! Just slap your plastic!!
--
(Grindage is used in this context as meaning shitty, rotten, lame, bunk, etc.)
See