After drinking to much water on a long car ride and needing to go to the restroom. You stretch your partners jaw open so far they get lock jaw, and then you proceed to urinate in there mouth to the point that it drowns them
P1. Hey bro, can we stop. I have to take a piss P2. We don’t have time to stop let’s just do a car ride porta-pody.
A fictional nationality similar to Portuguese from the make-believe country of "Porta-Gway".
I think the young chap is of Porta-Gweeze heritage, not Mexican or Portuguese.