Knock Knock!

It was a movie time with a friend and one of the scenes had a funny knock-knock joke in it. As I was enjoying the joke, I expected some company (and maybe even a hi-five... lame, but thats how we guys are), but found no expression as he was still not acquainted with knock-knock jokes. So, what happened next was the funny part - I paused the movie and explained how knock-knock jokes went and also gave him an example

Me: Knock Knock
He (me as he): Who's there?
Me: Boo
He (me as he): Boo Who (boo-hoo)
Me: Ok, don't cry, I was just joking.

The demo was done; I thought I did a good job, but how good it turned out to be, I had no clue. So, I tried a knock-knock joke and so I went -

Me: Knock Knock
He: I have to tell who?
Me: No, you don't have to say, 'I have to tell who?', but 'who's there?'
He: Ok.
Me: So, here...lets try again. Knock Knock.
He: Who's there?
Me: Shallbe
He: Who is Shallbe?
Me: Whew... why do you care? It should be "Shallbe Who?".
He: Ok.
Me: Shall we try again, then? Ok, here we go. Knock Knock
He: Who are you?
Me: What the ff....? Who are you? Screw it, let's watch the movie.

Well, the joke should have been
He: Shallbe who?
Me: Shall-be around later.