Yeah, I know Angel didn't leave her because he fed on her, that was my failed attempt at being facetious. I do, however feel like Buffy being fed on has a sort of symbolic significance in each of her relationship story arcs. Being fed on by a vampire is a very feral, animalistic act in its self and when Buffy, a symbol of purity, is physically drained by someone she trusts and loves, I feel like it holds great significance, at least story wise. It seemed like him feeding on her was an eye-opening moment in which he realized that they aren't good for each other. She would do anything for him, even if it involved him draining her of her last drop, this is a huge turn around from the Buffy that sent him to hell for the greater good. Dracula biting Buffy was also a huge factor in the Riley breakup. The act was brought up on many occasions during her relationship and was described, by Riley, to be one of precipitating factors to the end of their relationship. I could be just looking to far into this but with a showrunner like Joss Whedon, i wouldn't put it past him to use spike's feeding as a way to put an end to their relationship, either as direct cause or an extra straw added to the camel's back.
