Part 8 of the Wake Up Dead series.

Stiles drags his teeth out of Derek's throat and rolls onto his back. He's blood-drunk and sated, his body still aching from the sex that's never gone stale as long as they've been together. The aches fade as he licks his lips, catching the last drops of Derek's blood that hang on them.

"We've gotta talk," Derek breathes.

The words are soft enough that Stiles knows they won't be heard upstairs. It's only Cora home anyway, the rest of the household are at work or at school, but for some reason Derek doesn't want her hearing.

Stiles pulls himself up onto his elbow. "That sounds ominous." His voice is pitched just as low. "What's wrong?"

Derek was quiet all night. When the sun rose and they retreated to their room in the basement, the sex was intense, almost desperate. Stiles thought nothing of it, because Derek was sometimes like that. They've all lost people over the years, they all handle it in different ways, and Derek broods. It's just what he does.

He's silent now, too, gazing up at Stiles, his eyes pleading.

Stiles clicks his tongue. "Come on, Derek. Talk to me." He reaches out, brushes hair, damp with sweat, off Derek's forehead. He bends his head, drops a kiss to the outside corner of Derek's eye where the laugh lines are deepening with every year that passes. "Tell me."

"I can't do this anymore," Derek whispers. "I'm sorry."

If Stiles' heart could beat, it would have stopped. Instead, Stiles focuses on Derek's heart as it pounds hard in his chest. "What?" he says. He forces a smile, shakes his head because he doesn't want to understand. "I don't—"

"You know," Derek says. He reaches up, cups Stiles' cheek, drags the pad of his thumb down Stiles' cheekbone, over his lower lip. "Look at you. Still so—"

"I'm thirty-nine," Stiles snaps. He pulls his hand back and sits up, pulls the corner of the sheet over his hips and hugs his knees.

Derek's hand settles warm over the small of Stiles' naked back. "I know, Stiles. I know. It doesn't change the fact that we look wrong together. I'm close to fifty, and you look seventeen. You're always going to look seventeen."

Stiles sighs. "You don't look anywhere near fifty." He doesn't. With the benefit of werewolf healing, by human standards he looks forty, tops. "Besides, no one but the pack ever sees us together together. They understand, Derek, and I don't care. You know that."

"I do" Derek says, and then he sits up, wraps his arms around Stiles' shoulders, presses his lips to the top of Stiles' head. "But it's over. I've made up my mind and I'm not going to change it."

Stiles stares at the weave of the sheet bunched in his lap. Each thread is visible, every tiny fiber that runs through it, it's all clear to him if he looks closely enough. He's got to do something to take his attention away from the steady beat of Derek's heart, because if Stiles admits that Derek's telling the truth, that he won't be swayed, he just might fall apart. "I love you," he says, as though it might make a difference, as though Derek doesn't already know. "You said you'd always be here," Stiles says. "You said you'd never leave."

Derek moves behind him, slides off the side of the bed. "I'm not leaving," he says. "I just—" He falls silent, except for the sound of fabric moving over skin as he pulls his pants on. "You're not free, like this. You should be with someone who can keep up with you. Someone younger."

Most of the time, Stiles moves at werewolf speed. He's trained himself to slow down, to match the movements of those around him. He doesn't care about that now.

Derek blinks, because to him it must seem as if Stiles simply appears before him out of thin air. Even Derek's eyes can't track him when he moves at full speed. "No one can keep up with me," Stiles spits. "I'm a fucking vampire. Do you have any idea what I would give to look my age? To be able to grow old with you? To have been able to go to my dad's funeral? I've been officially dead for fifteen years, Derek, but I'm always going to look like I'm in high school. I'll never be free, not completely. Taking yourself away from me is not going to change that."

Derek doesn't flinch. "We always knew it would happen, Stiles. You'd have to move on." He sets his jaw, lifts his chin. "It's time. I've made up my mind."

Something in Stiles deflates. Derek's stubborn. Stiles knows he won't change his mind by talking. "I won't," he says. "Never planned to, not as long as you were alive. This doesn't change anything."

Derek shrugs and looks away. "I'm sorry." He heads for the door at the bottom of the stairs and looks back one last time. "You'll thank me," he says, and then he slips through the door and closes it behind him.

Stiles listens to him climb the stairs, listens to the door at the top open and close. He listens to Derek slump against it, his heart beating too fast, his breath shaking. "It doesn't change anything," Stiles says, loud enough for Derek to hear. "It doesn't."

Derek pushes away from the door and walks out of the house, his footsteps slowly fading as he walks into the sun where Stiles can't ever hope to follow.