The Friends season 8 decision to have Joey and Rachel hook up has long confused fans.
The show's bosses have now admitted they knew the romance would be "controversial" and loved that it was "wrong", reports The Sun.
The pair began an on-screen relationship after several years of Joey flirting with Rachel.
The creator of the show David Crane has now said: "The Joey/Rachel thing I know is controversial.
"I love it. I love it because it's wrong – and we knew going in: this is wrong. And that happens in life."
He added: "There is the relationship that shouldn't be. Even though you love someone, that's not who you're going to be with."
The romance might have been short-lived, but Crane added that it allowed Matt LeBlanc to play the part "he hadn't gotten to play yet".
"Joey and Rachel, we always knew (it would end)," he told the Radio Times.
"She was pregnant with Ross's baby. We always know this was like … that this was doomed, but in a hopefully really interesting, moving and compelling way."
Rachel and Ross eventually ended up together, and in the pilot episode of spin-off show Joey, it was revealed that they had married.