Keefian slip

A statement that highlights something already obvious. Often occurs when a joke goes over someone's head.

"Nah, I'm gonna flunk this exam. 0% for sure."
"Wait, how? You're great at that subject!"
"That was the joke, man. Keefian slip?"

Keefian slip

To point out something already obvious in conversation; often the result of missing sarcasm or having nothing to say.
Name comes from "kief", another word for cannabis crystals, thus roughly translating to 'a mistake made when high'.

(Math nerd): "Dude, I'm going to absolutely flunk this exam. 0% for sure.
(Friend): "Wait, what? But aren't you amazing at math?"
(Math nerd): "Yeah... that was the joke. Keefian slip?"