11:40 AM PT -- A spokesperson for Sesame Workshop has countered Saltzman, telling TMZ ... "As we have always said, Bert and Ernie are best friends. They were created to teach preschoolers that people can be good friends with those who are very different from themselves."

They continue, "Even though they are identified as male characters and possess many human traits and characteristics (as most Sesame Street Muppets™ do), they remain puppets, and do not have a sexual orientation."

Frank Oz -- longtime puppeteer for the show and hands behind some of the beloved characters, including Bert -- also denounced Saltzman, saying, "It seems Mr. Mark Saltzman was asked if Bert & Ernie are gay. It's fine that he feels they are. They're not, of course. But why that question? Does it really matter? Why the need to define people as only gay? There's much more to a human being than just straightness or gayness."

Bert and Ernie are finally out ... a "Sesame Street" writer is confirming the iconic characters are a gay couple.

Bert and Ernie have been on the show since it started in 1969, and there's always been speculation about the true nature of their relationship. Mark Saltzman, who joined the "Sesame Street" crew in 1984, cleared it all up by telling Queerty he wrote Bert and Ernie as a gay couple.

He says the 'Sesame' duo is a reflection of his own same-sex relationship and not about pushing an agenda.

Mark says he based Bert and Ernie on his relationship with film editor Arnold Glassman -- Mark was Ernie and Arnold was Bert.

Of course, Bert and Ernie have shared a basement apartment at 123 Sesame Street for the last 49 years ... although they've always slept in separate beds. Still, their chemistry -- while playfully arguing and bickering -- was always palpable.

Mark's revelation might be more of a formality -- the fact is, Bert and Ernie are longtime gay icons for many in the LGBT community.