1 Xander is going to commit suicide when Spike turns up and shows him what would have happened if Xander had never existed including Spike being dusted to make Xander change his mind.
2 Spike and Xander have been in a secret relationship when Spike is badly injured in front of the others (protecting Dawn?). To everyone's surprise Xander offers Spike his blood to help him heal so they all find out. They take Spike to Giles' where Giles says hes not gonna let Spike bleed out on his couch. Spike is sad afterwards about drinking pig's blood when he has tasted Xander. I think its a multi-chaptered fic. Also I think it might be Willow's fault in a way. For a while Spike is left alone with the others while Xander leaves the room and they try and ask him what happened between him and Xander- Buffys sullen.
Thanks for any help.