knock knock; with a twist

knock knock
whos there?
knock knock
whos there?
knock knock
whos there?
knock knock
whos there?
knock knock
whos there?
knock knock
whos there?
knock knock
whos there?
knock knock
whos there?
knock knock
whos there?
knock knock
whos there?

You can go no as long as you want for; until they say knock knock who. For people who know the joke it goes like this

Knock knock
Whos there?
Knock knock
Knock knock who?
Knock knock you!

It's fun waiting for them to click on their supposed to be saying
Knock knock who
instead of
whos there

So that's the twist.