I'm actually looking for a fic similar to the one in the last post. It involved Xander being hot and Spike/Angel being cold, but it had more to do with Hyena!Xander and being in heat or something like that. I can't remember which vamp he ended up with (maybe both) but I'm pretty sure there was a couch involved at some point and one of the girls looked in the room through a window and saw them.
This was two or three years ago, so if anyone can help out with this it will be greatly appreciated.
EDIT: Found by demonspot - it's "Resident Evil" and can be read here.