I found this if anyone cares. It's the original American folk tale from the 1940s that the porn flick is based on. There are alot of version, because the story changes as it's passed along. I was going to post the whole story here, but I decided on a link instead. I guess it was hot back then. It's very tamed by today's standerds. It's just a curiosity piece.

http://www.asstr.org/files/Collections/Alt.Sex.Stories.Moderated/Year2000/22590

The story is said to be the inspiration for a 1950s hit song from the 50s

The Green Door

-Artist: Jim Lowe
-peak Billboard position #1 for 3 weeks in 1956
-Words by Marvin Moore and Music by Bob Davie

{music includes constant "tick-tock" clock sound}

(Midnight, one more night without sleepin')
(Watchin' till the mornin' comes creepin')
(Green door, what's that secret you're keepin?)

There's an old piano
And they play it hot behind the green door
Don't know what they're doin'
But they laugh a lot behind the green door
Wish they'd let me in
So I could find out what's behind the green door

(Knocked once, tried to tell them I'd been there)
(Door slammed, hospitality's thin there)
(Wonder just what's goin' on in there)

Saw an eyeball peepin'
Through a smoky cloud behind the green door
When I said "Joe sent me"
Someone laughed out loud behind the green door
All I want to do is join the happy crowd behind the green door

(Midnight, one more night without sleepin')
(Watchin' till the mornin' comes creepin')
(Green door, what's that secret you're keepin?)

(Green door, what's that secret you're keepin?)

Green door!!