Excellent observation; that actually may be where it all started.Everyone after that point was doomed - she was always going to hold on to a core something that would protect her.
While we were watching Monday I think the issue was wether or not Buffy was using Xander with that whole dance thing... or thats what Kean and Sco said they'd gotten into Saturday. I don't think she was using him... I think it was more of a cruel teasing, like she was purposefully setting out to make a fool out of him and hurt him... why she exactly did that I really still don't understand, other than just feeling like being a bitca to hide her true emotions? But I don't think it was using, cause I mean, she didn't stand do gain anything from doing that to him.
She used him to piss Angel off. She knew that Angel was jealous of Xander and wanted to push his buttons. Xander got to be the guinea pig. She was messing with his head because she knew that Xander liked her. It was cruel.
Yeah okay, that does make sense... I forgot for a second that Angel was there watching, but yeah thats right she'd just gotten done talking to Angel right before she went and danced with Xander... watching and typing when the TV is behind me is very bad 😉