1: The fist fic was loosely based on the Saga of the Volsungs. Xander has to get married to a vampire and there is a test that the potential suitor has to go through were he has to walk through a ring of fire to get to Xander. Spike gets through that ring of fire but he has to leave for some reason and Xander gives a badly worded promise to marry the next person who walks through the ring of fire even though he is already in love with Spike. Spike comes back but he forgot he was there before as well as forgetting Xander and so he actually there because Angle is too much of a wuss to get Xander for himself. And that most of what I remember of that one and I think it ends with Spike and Xander getting together but I’m not sure.
2: The second fic was one where Spike and Xander are living together in an apartment in Sunnydale. I think Spike has a soul in this one and Xander a crush on Spike but he thinks that Spike is still in love with Buffy. Spike and Xander end up together and Xander wants to tell the rest of the group but just as he’s about to tell everybody Spike makes it very clear that he doesn’t want Xander to tell anybody. Leaving Xander very insecure about there relationship and thinking that Spike still wants Buffy even though that’s not the case. I’m sure this ends happily with the gang knowing about them and being okay with it but not before there is a bit of angst thrown in. ^^
EDIT: Both have been found. Thank you to darkhavens and mygothangel for all the help.