Two characters in the iconic US sitcom Friends, Monica Geller and Chandler Bing, were never meant to marry in the long-running TV series, says co-creator Marta Kauffman.

They were only meant to have a fling, Kauffman said at a panel at the ATX TV festival.

She said the pair, played by Courteney Cox and Matthew Perry, first got together during season four. When that happened, the audience fell in love with the new couple and wanted more.

"We had no idea what response that was going to get. We had to stop [taping] the show because people were screaming," she said.

Following the reaction from fans, the show's creators had to change the original plans they had for the couple.

"We thought it was going to be funny and we were going to get rid of it. Suddenly, the audience told us they had been waiting for that and we had to rethink how we were going to keep going and change the relationship. But that wasn't a person – it was an entire, immediate expression of joy," she said.

Rachel and Ross were made for each other

On the other famous couple on the TV show, Rachel Green and Ross Geller, played by Jennifer Aniston and David Schwimmer, she said they were always going to end up together.,

The show's writers had considered keeping them apart in the last episode "for about four seconds."

"That would have been dumb. In the very first episode we see that he loves her," she said.