i was about thirteen. it was a church bus. maybe about 10, 15 kids in this ancient schoolbus, the kind with a row of wide windows above the seats.
i was already used to the idea of "when in road trip mode, hold it for hours" it didn't even occur to me to ask the driver to stop. i peed into a bottle but i had to go #2, man. so i fit my entire ass and thighs and most of my lower back out the window, hooking around the window frame with my knees, i got someone to hold my arms i was worried about going over a bump and falling thru.
then just pwerp pwerp dropping turds on the highway. i don't remember who was driving. wiped my butthole with a paper bag.