The act of engaging orally with your partner, proceeding to extend your tongue into his/her mouth until touching the
uvula. This will cause gag reflexes, and causing your partner to vomit into your mouth sending a satisfying
waterfall of
barf into your throat, exchanging back and forth.
"Hey man, what did you and that girl do last night?"
-"
Not much bro, just a quick Mexican Border Exchange.
She ate hotdogs!"