15 Things We Learned From Friends: The Reunion
6. Monica & Chandler Were Originally Supposed To Be A Fling
According to Marta Kauffman, Monica and Chandler's hookup in London was originally intended to be a mere fling, but after seeing the studio audience's response to them ending up in bed together, the decision was made to run with it.
Even once they committed to something beyond the one night, though, there was the expectation that it would be focused mainly on Monica and Chandler comedically hooking up in secret while trying to avoid the rest of the group.
Ultimately, however, the feeling was that the dramatic dynamic was too strong to disrupt, and so the pair became an outright romantic pair for the show's remainder.
The lesson here? Always listen to the audience.