u/Cats-and-Sunshine

I'm doing a re-watch of the series, and Leo shows up for the first time at the end of S1 E3 Thank you for not Morphing. Phoebe is the one who shows an immediate interest in Leo and flirts with him a little, Piper doesn't seem all that interested. It's only in E7 The Fourth Sister where Piper shows interest, and she and Phoebe have their little fight over his attention, and then in E8 where Phoebe says under the truth spell that she's only interested in Leo because Piper is.

So, was it a retcon of E3 to play into the whole Piper and Leo were meant to be storyline, or a case of inconsistent writing?