When Knock-Knock Jokes Attack

Arielle and her friend Jacob have discovered knock-knock jokes. It turns out that Jacob's mom, on the days she drives them, has been trying to teach them the knock-knock joke that goes:

Knock-knock
Who's there?
Banana
Banana who?

Knock-knock
Who's there?
Banana
Banana who?

Knock-knock
Who's there?
Orange
Orange who?
Orange you glad I didn't say banana?

Arielle got it; Jacob didn't. So today, on the way home from preschool, I got to be entertained by them slinging knock-knock jokes back and forth. Jacob took the lead, which meant we got this:

Knock-knock
Who's there?
Banana
Banana who?

Knock-knock
Who's there?
Apple ... or apple tree
Apple ... or apple tree who?

Knock-knock
Who's there?
Orangeappletreedirtytelephone
Orangeappletreedirtytelephone who?

We never did reach a punchline, but the kids seemed mightily amused anyway!