it's driving me nuts. i keep thinking of 'hold me, thrill me, kiss me, kill me', but i know that's /not/ it. it's a spander, obviously, and i thought i'd seen it on spanderfiles, but i can't find it, so it may have been livejournal or the crypt or aff or ff.net, and i just don't think i can search all those things myself.
what i remember is that it's a rewrite starting at the episode where xander does the love spell. instead of all the girls falling for him, it's the boys. including spike and giles. those two ended up cornering him in the empty bronze during the day, and the spell breaks.
spike starts stalking xander, who starts developing feelings for spike. however, the scene that is really sticking out to me is in the library. xander was living with giles after getting kicked out of the house (for being gay?), and he made a remark about his parents, which the girls laughed at. after they left, giles was angry that they hadn't taken him seriously, and xander explained it was a joke, and that even giles hadn't believed it until he'd found him living on the street and taken him home where xander was threatened by his father. the girls overheard this and there was much crying and apologies.
there's another scene where xander took the trash out, and he and spike had an argument/make-out session by giles' garbage cans.
ANYWAY!! if you know what or where this is, i would greatly appreciate the info!!~
edit: thanks to those that helped! the answer is 'sour revenge' by flufshepherd.