To whom is Willow speaking?

Anya, natch

"Good," said Anya as she entered the house and went straight to the living room. "Xander and I had a fight and I really don't feel like being by myself right now. Er, he's not here, is he?"

"Why would Xander be here?" asked Willow.

"You know why."

"Oh, that. Like I told you before, Buffy and him are just friends."

"Just friends, huh?" said Anya. "If I recall from my days as a justice demon, it was friendships like that that kept people like me in business."

"Anyway, he's not here right now so it's safe to come in -- oh, wait, you already came in. I keep forgetting your unique take on common courtesy."

"It's okay. I hope I'm not disturb -- Oh, my God! Willow! Look what just came out of Buffy's kitchen!"

Willow turned around. "It looks like -- No, it couldn't be. Could it?"

"What's the matter, guys?" asked Buffy, as she entered the living room while munching on an enormous carrot. "And why are you and Anya staring at me like that? And -- My God! Anya! You look as white as a ghost. Is there something behind me?"