A Gamble
When you don't know if you're going to poop or fart and you just decide to take a chance.
I was in the middle of a bet and had to choose between farting or pooping and I picked both.
My brother said he would eat a whole pizza if he pooped first. He pooped and then farted.
I bet my friend $10 that I would fart before I pooped. I farted and he cried.