When the apology finally comes, it's...anticlimactic. To tell the honest truth, it's more post-climactic; at least, it's post-climax.
"I'm sorry I tried to have you killed." The words are whispered against Spike's shoulder, damp with sweat that isn't his own. They often wind up like this, Spike's back to Giles' front. There's truth in the post-climactic calm, and the truth about these two is that one likes to be held and the other likes to hold. In the harsh light of day it doesn't matter who's stronger, but in the dim bedroom truth often comes out in unexpected ways.
"I'm sorry I tried to kill your Slayer so many times." It seems only fair, to trade an apology for an apology, even one wrapped up in so many layers of pain.
In this room, in this city that spawned them both over a hundred years apart, it's easier somehow to focus on the distant past, rather than the recent. They don't speak of Angel, who was important to both of them in ways so disparate as to be on nearly separate planets. And they don't speak of what it meant to each of them when he fell to the dragon. They also don't speak of Buffy by name, nor Ethan, nor Wesley - they may be as close as two people can be, but there are some chasms that won't be bridged.
It doesn't bother them much - they have other things to speak of; training and other Slayers and Council business and prophecy and more. They are comfortable; they are together. They both know that the day that the comfort ceases, so will the togetherness, but between them they've gathered enough wisdom to live in the moment.
"I'm sorry I couldn't save you from him sooner," Spike says, twining his fingers with Giles' bent and scarred ones. It's a truth that needs telling, soul or no.
Giles kisses Spike's shoulder and sighs and tells a truth of his own. "I'm glad you're here."