A Buttfuck
A buttfuck is a brainless meat sack who thinks they're the smartest person in the room, but they're really just a walking disaster.
My cousin is a buttfuck. He failed math and still thinks he's Einstein.
The guy at the gas station is a buttfuck. He talks to the vending machine like it's his ex.
My teacher called me a buttfuck because I drew a mustache on her face.