Willow and Anya's dislike for each other seemed to come out of nowhere. Why was it decided to set the two characters against each other?

A lot of Triangle did have to do with animosity between Willow and Anya. It had been set up before, but very lightly in the Thanksgiving episode Pangs which I wrote in a previous season.

There was a line that Willow said about the best thing about having Thanksgiving dinner is that "We can not invite Anya." That was actually a line that Joss had suggested I put in the script. I was a little surprised by that line, because I hadn�t realised that there was such dislike between them.

Then, two seasons later or whatever, it pays off, so I go, "Okay Joss". Joss saw an animosity there, he was encouraging us to build that in from early on. It might have been nice if we�d even been able to do more of that, because it would have helped do some of the stuff that we had to build up in the course of doing Triangle. But I think in his mind it was always there, so it just shows, he always knows.