face vault - A face vault is when you drop to the floor like a dead fish

A face vault is when you drop to the floor like a dead fish because someone said something so dumb it made you want to die.

My cousin face vaulted when my uncle said he could live in a toaster.

I face vaulted during science when my teacher said the moon was made of chocolate.

My friend face vaulted when his dog said he wanted to be a superhero.