When someone "calls someone out" or makes fun of someone else. Good checks are funny. Usually when someone is checked, other people will laugh and sometimes join in to the "checking games"
Me - "Brandon you're so ashy, I could start a fire with you're dang kneecap."
Brandon - "Bruh why you gotta check me!!?"
Me - "Britney you need to be checked for that shirt, it looks like a dirty dishrag"