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!"
-"Not much bro, just a quick Mexican Border Exchange. She ate hotdogs!"
by kevinhysonronlamoreboofinda941 September 28, 2010