If you're not still watching The Simpsons, now in its 22nd season on television, then you may have missed the controversial couch gag storyboarded and written by graffiti artist and political activist Banksy. The sequence, which has made the viral video rounds in the days since it first aired, takes aim at The Simpsons' use of animation studios in South Korea, painting an exaggerated but grim portrait of what those labor conditions might be like, including the use of decapitated dolphin heads to glue packages shut and the sharpened horn of an ailing unicorn to puncture holes in DVDs.

It was a controversial sequence for the animated series, to say the least, but not one that went unnoticed by 20th Century Fox. In fact, as Simpsons producer Al Jean explains it, Fox signed off on the sequence well in advance of the episode's airing.

"[It was] approved by them," Jean told The New York Times. "Obviously, the animation to do this was pricey. I couldn’t have just snuck it by Fox. I’ll just say it’s a place where edgy comedy can really thrive, as long as it’s funny, which I think this was. None of it’s personal. This is what made The Simpsons what it is."

Jean added that 95% of Banksy's original vision wound up in the final cut of Sunday's episode, with five percent removed "for taste."

"I’ll just say, it was even a little sadder," the producer said of the original cut. "But I would have to say almost all of it stayed in. We were thrilled."

As for whether or not Fox is having second thoughts now that the bit has aired, Jean said: "I think that we should always be able to say the holes in our DVDs are poked by unhappy unicorns."

Watch Banksy's controversial couch gag below.