ka-doink, boink
A word you shout when someone makes a mistake so obvious it’s like they’re blind and stupid. You might even punch them in the face if they keep doing it.
My brother said, 'I can’t believe I spilled my juice.' I boink-ed him and said, 'You’re an idiot.'
My sister said, 'I can’t believe I wore my socks inside out.' I boink-ed her and took her socks and threw them in the trash.
My dog said, 'I can’t believe I ate my homework.' I boink-ed him and gave him a time-out.