It's S6 but when Buffy comes back all her friends seem to abandon her. Spike sticks around though. Helps her buy stuff, takes care of Dawn, gets a job as a bouncer at the Bronze(Buffy goes there to pick up Dawn's notebook once and sees Xander and Willow who complain about her not partying with them). I think it was also the one where everyone(a lady at the supermarket, a boy Buffy studied with, even Dawn and Tara) tell her he's her boyfriend and she corrects them. He lives in the basement and in the end Buffy tells him to come up to her room where he belongs.
Someone is looking for this over on BTVS Fanfiction Search Community. I know it but can't remember title and it's really bugging me. | 
