Inside Oprah Winfrey and Gayle King's Best Friend Cover Shoot for 'O' Magazine (Exclusive)

ET takes you behind-the-scenes of the best friends' cover shoot.

Oprah Winfrey and Gayle King are #BestFriendGoals.

The two BFFs cover the friendship-themed September issue of O, The Oprah Magazine, on newsstands Aug. 13, and ET has your exclusive behind-the-scenes look at the fun photo shoot.

Dressed in shades of matching gold and beige, the CBS This Morning co-host joked about being on the cover of Lady O's publication.

"I'm on the cover? Did anybody check with Oprah?" King jokingly said, adding, "They said it was Oprah's idea." Sharing the cover with King is a big deal and extra special, as Winfrey has done almost every single one alone -- that's more than 230 shots.

The issue is all about friendship, and Winfrey and King go back more than 20 years. The two first met in the '70s when they worked together at a Baltimore, Maryland television station. Since then, both of their careers have taken off!

"People come up to me all the time and introduce their friends to me as, 'This is my Gayle,'" Winfrey told ET's Nischelle Turner. "So I think it means something. Someone asked me the other day, how is it that our friendship has lasted so long. It's because she has a life of her own and now people can see that she has a life of her own."

"I think people were surprised when they started seeing her on CBS," Winfrey shared adding that, "People were like, 'How did you learn TV so quickly?' She's been doing it FOREVER!"

As for King, she took to Instagram on Wednesday to share her stunning cover, as well as share a sweet message to her best gal pal.

"We’ve been friends since we were 21 and 22 ... forty plus years later here we are!" she began. "Our first (and never to be duplicated) @oprahmagazine cover! we have each other’s backs always I believe it’s called 'ride or die' ...@oprah is the truth in all things full stop... this was suppose to be an inside shot and the o of o said make it a cover ...thanx Oprah!"

See more on the besties in the video below.

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