Toilet humour is a type of funny talk or jokes that often involves things that happen in the bathroom. Like when someone makes a funny fart noise or talks about poop.
It's kind of like a silly game where people try to make each other laugh by saying or doing things that are related to going to the bathroom. Even adults find these things funny sometimes, but it's important to remember to be respectful and not hurt someone's feelings with our jokes.
So, like when you're playing with your friends and someone makes a funny noise with their mouth, and everyone starts laughing, that's kind of like toilet humor! But remember to always be kind and not make fun of someone if they don't want to participate in that type of fun.