They are... Not Hers
Deep down inside, Buffy knows her feelings are miserable and petty and wrong. She knows she has no right to resent Willow or to deny Spike the right to find something more than the crumbs she offers him. Knows that she's been a hypocrite all this time, condemning Willow for a frailty she's all too familiar with and making her pay and pay for transgressions she herself has barely gotten a slap on the wrist for. Knows that it's cruel and inhuman to use Spike's love for her to make him into her sexual slave, to treat him like dirt and use him to satisfy her own desires without a care for how much pain she inflicts on him.
She can't help it, though; she hates them. She hates Spike for not being there for her anymore, for not letting her fuck him to make herself feel, for not letting her feel superior by degrading him, for not loving her anymore. And she hates Willow. Hates her for ripping her out of heaven, but also for not being in her orbit anymore, for not caring so much about being her friend and earning her forgiveness and making things up to her that nothing else exists in her world. She hates them both for escaping from the pull of her gravity and not being her satellites any longer.
Deep down, she knows what she feels is childish to a degree that is monstrous. Somewhere in her heart, she still has enough of that humanity she tells herself she came back without to realize that what she's been doing to Spike is vicious and wrong, enough of the love and affection she's always felt for the best friend she's ever had to realize that she should have forgiven Willow long ago, and that she's losing the best thing in her life by pushing her away. Buffy knows that if she's smart, she'll act like a grown-up and accept this-thing-between Willow and Spike before her anger costs her so much more than paradise. But she's not ready to grow up just yet, so she clings to the small, selfish part of herself, clutching it tightly as if it were Mr. Gordo. Right now, she just wants to hate them, and she does.
They are... Wrong; so, so wrong
He can't figure out how this could have happened. She's his best friend. Sure, since the whole magick-addiction thing, he hasn't been around her as much, but that's because she needs to see the error of her ways, to understand that her actions have consequences, to... There's a whole, complicated explanation the others had given him from all these books on dealing with addicts, but Xander has never been good at remembering those things. He just does what smarter people, people who care about Willow as much as he does, told him was the right thing to do. But if they've been doing the right thing, then how did his best friend, his gay best friend, wind up with Spike?
He doesn't understand. What about Tara? The last time he'd talked to Willow, she'd been desperate to win back her lover, desperate for all of them to forgive her so that things could go right back to the way they were. It couldn't have been that long since he'd sat down with his best friend, could it? When did she stop wanting for everything to get back to normal? When did she stop caring about atoning for the bad things she had done and earning their forgiveness? And when did she start caring about Spike?
There's a part of him, deep down, that's jealous, though he doesn't like to think about it. Sure, he stopped wanting Willow a long time ago, but he never wanted her to stop wanting him. He got comfortable with the idea of Oz, seeing him as the guy Willow settled for after she and Xander never worked out. And Tara, well, Tara's a girl, and that's not something that he has to compete with. But Spike... Spike's a whole other ball game. If Willow's with Spike, it means she doesn't love Xander at all anymore, not the way she used to; and out of all the things that Willow has done, the fact that she's stopped loving him is the one thing that Xander can't forgive her for.
They are... Traitors
It's just not right, and even though she's an ancient mystical Key, this whole thing makes Dawn feel more like a broken-hearted teenage girl who's lost her first love than a shiny ball of energy. She feels angry and hurt and betrayed and vengeful. She wants to break everything in her room, to scream so loud the whole neighborhood can hear her, and to cry until she falls asleep and wakes up to find out this is all only a nightmare.
But it's not, and she knows that. Spike loves Willow. Willow. The girl who called her names and treated her like a baby and almost got her killed. Dawn was Spike's pet, his Lil' Bit, and, at least in her dreams, his future girlfriend. How could he betray her by falling in love with Willow? And how could Willow betray her by falling in love with Spike? Not only is she betraying Dawn but she's betraying Tara, sweet, caring Tara. Doesn't Willow realize that all Dawn wanted was for the two of them to get back together? Then she would have forgiven Willow, too, and everything would have been wonderful again. Like before, when Buffy was still gone and Willow and Tara had made her feel safe. Only it would be better this time, because Buffy's alive again.
Now, though, now nothing is ever going to be the same. Tara is never going to move back in, Buffy and Willow will never be friends again, and, worst of all, Dawn will never be Spike's girlfriend. She hates them both. But most of all, she hates Willow.
They are... Together
She should have known this would happen, Tara tells herself over and over; she should never have fallen in love with a girl who'd had a boyfriend before. She's always known that Willow would do this, would head back to boystown. She's just been a quirk. The college experiment, like drinking or drugs or a Spring Break threesome, that every girl has in the scrapbook of her memory. A souvenir of carefree youthful abandon, put up on a shelf the day after graduation, never again to be more than a story relived over martinis at the ten year reunion
She knows these thoughts are wrong, though, even as she has them. Willow loved her. It was real and true and special. Was. That's the word that hurts, that makes Tara tell herself she was just a fling over and over again. Because this ending would be so much easier if she could just believe their relationship had been meaningless to Willow. That she'd been used and tossed aside. Instead of the truth. That she's stupidly thrown away the most wonderful woman she'll ever know. Because she was scared, judgmental, and too stupidly arrogant to think that anyone could take Willow away from her, even if she wasn't around anymore.
Oh how wrong she had been. Still, how could she have known to fear Spike? He was Buffy's. She'd even seen them together, knew that Buffy and Spike were having sex on a regular basis. When had that changed? When did Spike turn his eyes away from Buffy and see the shining, bright thing that was Tara's and decide to take it for his own? Not that she can blame him. Since the first day she ever laid eyes on her, Willow has been all she can see.
How could she have been so foolish? Why did she abandon Willow, make so many demands, why had she been so harsh and unforgiving? If only she could go back, she would do it all differently, stay with Willow and pull her back from the brink some other way. But it's too late now. Spike will never make the same mistakes she did, she can see it in his eyes. As much as it hurts, Willow and Spike are together; Tara will never hold her in her arms again. Even though she knows it's wrong to feel this way, a part of her almost hopes that someone stakes Spike.
They are... A good thing
She wishes she'd been there for the big announcement, or announcements, really, but Anya's not all that surprised that she's had to hear about this second hand. After all, it's not like she and Willow are really all that close. She and Spike aren't either. Of course, there's the fact that they're both demons, but that has never made them very close. She likes Spike, would even have sex with him, but that's because he's attractive and she doesn't have to follow those silly human rules about sex having to be meaningful. Not that there's any chance of having sex with him now. Willow's the monogamous type and she'd be upset if Spike had sex with someone else now that they're a couple.
It makes sense, now that she thinks about it, this Willow and Spike thing. And if the others weren't so stupid and caught up in all their stupid human emotional crap, they'd see it, too. Willow and Spike make sense. They sure make a lot more sense than Spike and Buffy ever did. What was Spike thinking? Stupid question; he wasn't thinking. Just being all-too-human and thinking that an erection meant more than a physical interest in someone. Buffy is, after all, an attractive girl. But really, the perfect girl for a demon? Once again, what was Spike thinking? A witch, now that's a good fit for a demon. Especially now that Willow isn't such a good witch anymore.
Actually, now that Anya thinks about it, she really likes the idea of Willow and Spike. They make her think that anything is possible, even for her. So maybe she'll do something nice for them, call Giles, and maybe Angel, too, and tell them the news before Buffy does it and ruins everything by telling it her way and ending up getting Spike staked. Yeah, that's what Anya will do. She'll call them up and tell them about it the right way, so at least someone will understand that this is really a good thing, this Willow and Spike thing.
They are... Love
It hurts Willow that none of her friends can forgive her for loving Spike. Of course, she understands Tara's pain, and she supposes she couldn't have expected anything different from Buffy, or even Dawn, but she harbored a secret hope that Xander might care about her enough to want her to be happy, no matter what; that he felt the same way she has always felt about him. But he doesn't, and he refuses to even try, just insulting her and cutting her out of his life and, without knowing it, making her realize just how right the choice she's made really is.
Of course, it would be so much easier if she could just write them all off. Say, "Good riddance to bad rubbish," and be on her merry way. But Willow has never been able to excise anyone from her heart once they've become a part of her. Somewhere inside of her, she still loves Oz, after all. So, even as she loves Spike with all her being, a part of her heart will always be Tara's, and the part of her heart that belongs to them bleeds from the wounds inflicted by Xander and Buffy and Dawn.
Still, somehow, despite the pain she feels, she can't deny that she is happy, happier than she has ever been. She wonders how, after losing everything that, less than a month ago, was her whole world, she can feel so gloriously complete. But then she looks over at Spike and her confusion ends. How one person can now give her everything that her lover and all her friends put together were never able to give her before is a mystery she can never hope to solve. But it really doesn't matter. Because the answer to all the questions she needs answered is Spike.
He would like to say that he regrets what she had to give up to be with him. But that would be a lie. The happiest moment Spike has ever known, alive or undead, is the moment when Willow returned to the crypt in tears, telling him that she'd told Xander about her love for Spike and that he'd told her he never wanted to see her again. She'd cut the closest bond she had, given up the friendship she'd clung to since childhood, and she'd done it for him. His heart almost beat again just thinking about that day. It was that very moment that he realized just how much he had feared what might happen, that he'd been terrified that her friends would lure her back to the fold, that she'd decide to return to the safety of Tara's bed and give up Spike for the comfort and security of her old life. And it would have been hard to blame her. Choosing him means giving up everything that's ever mattered to her, but she's done it, and Spike knows that he'd better find a way to make her immortal, because it will take eternity to pay her back for all that she's given him just by making that choice.
It's a wonderful feeling, he realizes; this big, grand, terrifying thing between them. It's so far removed from what he felt for Drusilla, Angelus, and Buffy that he has to choose which one is love. What he felt for them or what he feels for Willow. He chooses what he feels for Willow. William might have gone on and on after that epiphany, pondering for endless hours about what name should be given to the feelings he'd had for those who had come before. But the word comes easily to Spike. Mistakes, that's what everyone before Willow was. Mistakes. Still, he doesn't regret a thing. Not a single moment spent with Dru or Angelus or even the Slayer. He's not much of a philosopher anymore, but he knows that the alteration of even one moment of his past might cost him the joy of his present. And that would be so much worse than any mistake he's ever made. He loves Willow and she loves him. It's real and true and forever. That's all that matters now.