Knock knock.
Who's there?
Robin.
Robin who?
Robin you, that is who.
"Knock knock?"
"Mustache."
"I mustache you a question, but I'll shave it for later!"
"Knock" "Knock" "Whos there?" "aarghraawa"
Why did Sarah fall off the swing? She had no arms.
What did Sarah get for Christmas? I dunno, she hasn't opened it yet.
Knock knock...
Who's there?
Not Sarah.
Knock, knock. Who's there? An armless person. Why? They got stumped on why they contacted you.
Knock, knock.
Who's there?
Boo.
Boo who?
Don't cry, it's just a joke!
Knock knock. "Who's there?" "Grandma." "Oh, okay."
Nah, it's a penis.