This may seem as a terrible self-pimpage, but I wrote a story that I think could fit the bill. It's not AH, but it's complete and there's plenty of Buffy/Spike banter.
Here's the summary

: Forced to be close together for an infinite amount of time, it stands to reason that mortal enemies would drive each other insane. But when it comes to a self-righteous, uptight slayer and an irritating, chipped vampire, there is no reason. This story, set just after S4, is full of banter and innuendo, so read on if you are interested. Also, Riley left to roam the jungle a little early so he isn't in the picture.
Here's the link (hope it'll work):
http://spikeluver.com/SpuffyRealm/viewstory.php?sid=36328&warning=NC-17In case it doesn't work, it's titled 'Denial'.
