Made a Grunny - You do your business in someone’s toilet and don’t flush it

You do your business in someone’s toilet and don’t flush it while they're out and wait for them to come back and face the stench

I did my business in my dad’s toilet and left it to smell like a rotting pizza.

I made a Grunny in my teacher’s toilet and she had to teach with a stinky butt.

I took a dump in my brother’s toilet and it stank like a million dead monkeys.