And don't forget that Ernie and Bert appeared on the Muppet show too, so they could of talked about SS with the other muppets.
That, and there's numerous refferences to it... So word MUST have gotten around.
I mean, Floyd, Nigel, Sam, and Brewster all saw the picture of Big Bird.
Bert was dancing during Sex and Violence.
Kermit said he could get a female whatnot a job on an edjucational TV show...
Kermit and Rowlf both pitched the idea...
Ernie and Bert where the second second guest.
Mahna Mahna was preformed on both shows...
Beautyfull DayMonster was on both shows...
Baskerville was on both shows...
Fozzie, George, Mildred, Piggy, Wanda, and Gonzo all agreed, like they've known about it for a while...
The Green Hunchback frackle was on both shows...
And I still beleive the Frank Voice that does Backstage work, is Cookie Monster, sounds just like him.
And Ernie and Bert met Mildred, Crazy Harry, Muppy, Rowlf, Brewster, Droop, George, Miss Mousey, and Wally.
Now, Kermit lived on Sesame Street, for quite some time... Whose to say he hasn't spoken about Sesame Street? I mean, how else would he have made the EMC for Muppet Show? Nigel and Wally where going to be the host...But Kermit was chosen...
I still say Gonzo knew of Sesame Street, but didn't know of Big Bird back then. Maybe he thought Big Bird was female, like most people do when they first see our yellow friend.