Every classic romantic comedy has one whether it’s a full-on flash mob or a more demure tete-a-tete.
Click through to read their untold stories.
I had to literally choreograph it in about two hours, he says.

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It was the definition of flying by the seat of your pants.
Shankman pulled it off, but co-executive producer Bob Weinstein had a note.
Bob kept saying, But how do these kids all know the dance?

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The whole thing was so ridiculous, Shankman says, laughing.
[They] had never been to a prom, Iscove explains.
I said, Im going to give them a prom to knock their socks off.

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Its a different, unique way to see two people argue.
While Marys passion swaps tangos gender roles, McConaugheys preparation made Steve a worthy opponent.
(McConaughey trained for two-and-ahalf months, while seasoned dancer Lopez needed only about three rehearsals.)

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He couldnt have done that if he didnt have those steps down perfectly.
Shes not being ironic about it; shes not goofing around, shes doing it.
If anything else, the number imparted joy to an entirely new audience.

20th Century Fox
We were the generation of the Thriller video, concludes Goldsmith.
The scene wasnt even in the original script.
I kept referring to it as the gayest day on the schedule, Berlanti cracks.

The dance makes for a vitally hopeful centerpiece.
So for most of that scene Imreallytrying.
Schumer became so comfortable dancing that she did it when she wasnt even required to do so.

David Lee/Warner Bros.
So I surprised him and full out did the dance for his reaction shot.
And you could see him getting emotional.
It was really sweet.

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Now thats what you call something borrowed.
And it mirrors how the films writer-director, Preston A. Whitmore II, celebrated as well.
This is just something that we naturally did with my family and many other African-American families, he says.

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On the day we were shooting it, everybody was just standing around, recalls Whitmore.
According to director Howard Deutch, the actor does a great Mick Jagger impression.
A different tack was required, and few singers have ever captured the sound of longing like Redding.

Michael Parmelee/Warner Bros.
Jon showed Kenny what he could do, and Kenny refined it.
He was a fan of one mounted by Oprah Winfrey, so he hired its choreographer, Ashley Wallen.
It was a very happy day [of shooting] for everyone, apart from Hugh.

Justin Timberlake and Mila Kunis in ‘Friends With Benefits’.Screen Gems
Still, that doesnt mean Grant didnt do his job.
Hugh was always the best prepared actor Ive ever worked with, Curtis explains.
In fact, perfecting the sceneafterwardproved a bigger challenge.

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The timing was very hard.
Consider it a labor ofLove.Shirley Li