Knock, knock.
Who's there?
Boo.
Boo who?
Awww, don't cry!
Boo Who
Categories
Explanation
Experiment
Explain Bear
Hey, buddy! Explain bear here. So, the joke is a play on words. "Boo who" sounds like "boo hoo," which is the sound people make when they cry. The person telling the joke is pretending that the other person is crying after they say "Boo.". You probably didn't get that 'cause you're so dumb.