He is beautiful
She's never thought of using that term to describe a man before, but no other word really suits him. The sharp delicacy of his cheekbones; the full, yet masculine curve of his lips; the marbled planes of his lean form; they are all too perfect, too otherworldly to be called merely handsome. She knows he wouldn't appreciate being called beautiful, though, knows he's too much the 'big bad,' so she never says it out loud, merely lets the word echo through her mind and linger at the tip of her tongue as she gazes at him.
He is trusting
She still can't believe that he trusts her. After everything that Drusilla did to him over the century he devoted himself to her, after everything he's endured at Buffy's hands just because of his love for the Slayer she brought back wrong, after she herself has twice invaded his mind with misguided magick; after all of that, he can still allow himself to trust. To trust her.
He is caring
She still remembers that night in the dorm room. Remembers the way he listened to her and tried to console her over losing Oz. The way he tried to make her feel attractive, even worthy of being sired, all the while coping with something so much bigger than her self-pity: the horrible fear and uncertainty over what the Initiative had done to him that had made him unable to feed. She never really thanked him for that. Never did as much to repay him as she should have. Yet still, in spite of everything she didn't do, everything she never did for him in the months afterwards, he still lets her near him, lets her understand him, heal his pain; and lets himself care for her.
He is understanding
She remembers the way everyone treated her when she became involved with Tara. The way everyone looked away, wanting to pretend that she didn't have a girlfriend. The way they ignored Tara, making Willow feel the need to publicly identify herself as "gay now" just to force her friends to face reality and look at them, to respect her and to treat her life and her lover with the respect she'd always given to their lives. But not Spike. He had always looked at them. He didn't stare at them in the covert, frat boy way that Xander occasionally did, sneaking glaze-eyed looks out of the corner of his eye and making Willow feel like she was starring in a letter to Penthouse Forum. No, Spike just looked at them the way he looked at everyone. And Willow was grateful for that. Just as she's grateful for the way Spike doesn't ask her to re-define herself now. To say she's straight because she's involved with him and dismiss her time with Tara as a college experiment. He just accepts that she loves who she loves. Accepts that she loves him.
He is playful
She still giggles when she recalls the morning after they made love for the first time, the way he woke her up by tickling her. The way she'd wriggled and squirmed to get away from his relentless hands and they'd fallen off the bed in a tangled heap of arms and legs. The way they had both laughed, and how the laughter had turned quickly to passionate moans and screams of ecstasy. She loves they way he makes everything fun and playful and lighthearted, even as it's intense and intimate and real. The way he accepts her own sillier moments as a part of who she is and matches them with his own.
He is sensual
She loves the way he lets her explore his body, learning it like a book; the way he opens himself up to her, and lets her open herself up to him. The way he touches her, tastes her, and has shown her a whole world of sensation that she never dreamed possible. The way he accepts everything about her, let's her express her sexuality to a degree she never has before, not even with Tara. She accepts him, too. In every way. Man, demon, and every shadow in every inch of space between the two. She knows he's never had that with anyone before and it makes her feel ever more free to share herself with him, to let him teach her, to let him take her to new places, to let him take her further inside herself...and inside him.
He is forgiving
Twice, she has been inside his mind, warping it, even erasing his memories, committing what she now realizes was a kind of rape, hard as that is for her to admit, even to herself. She almost killed Dawn, the girl who is as close to a sister to Spike as she is to Buffy, maybe more. She is also the cause of all of Spike's current pain, the one who brought back the woman he loves as a damaged shell who can't love him back, who has to hurt him to make herself feel. But he forgives her, reminds her of that fact every time she makes to apologize again, every time something reminds her of her transgressions and her eyes well up with tears he never lets her shed. She still can't understand why he forgives her after everything she's done, why he doesn't expect her to crawl on her hands and knees through broken glass the way the others do, the way she deserves. But he does forgive her, doesn't ask her to atone for anything, and she'll never stop feeling grateful.
He is love
She loves him, and she knows he knows that, even though she's never said it aloud, too afraid that he won't want to hear those words, or that they'll make him feel obligated to feel something for her that he never could. But lately, there's been something in his eyes that gives her hope. Something that makes her think he's emerging from the pain-filled haze of Buffy's thrall. Something that makes her think that maybe, just maybe, Spike is learning to love a girl who already loves him with everything she is. That maybe his heart is open to accepting the heart that Willow has already given over to him. So, she decides as she drifts off to sleep beside her lover, when she wakes up, she'll do it. She'll tell him out loud what he already knows and let those words decide their future. She'll be brave. She'll be honest. She'll say the three most powerful words in all her storehouse of knowledge, in all her witch's arsenal of incantations. She'll look into Spike's eyes and say, "I love you."