Oba yo
A low-class Mennonite way of saying 'I believe you' but it’s way louder and more intense, like when your dog eats your homework and you still say 'I believe you' but with a lot more yelling.
'Oba yo!' he said when I told him I got the last slice of pizza.
'Oba yo!' she said when I told her I beat her at video games.
'Oba yo!' he said when I told him I ate the whole cake.