"Would you care to let the rest of us in on the joke?"
When so many people are in on the joke, how long can it last?
Everyone was in on the joke and they had a good time with it.
He usually had two things on his mind, girls and jokes.
The whole bar seemed to be in on the joke now.
All the women seemed to be in on the wonderful joke.
Then she would laugh and let others in on the joke.
Not all his colleagues were in on the joke, though.
His eyes were dancing as though I was in on the joke.
The only solution, she decided, was to get in on the joke.