Spike stopped dead, staring at her. Getting souls back. "How did you--"
Oh, no, wait, Giles, he'd told Rupert. Rupert'd probably told Buffy. Spike hadn't meant to tell Buffy. Somehow his initial plan of get soul, become the sort of man she deserves, have her fall all over me and live (undeadly) happily ever after with enough sex to make even the hardiest porn addict bored of watching eventually had evaporated once he inserted the realizations of the sort of man Buffy deserves would never have done all that shit to begin with and she was using you and it was killing her, remember?
But she'd just promised not to leave him. Buffy always kept her promises. And with or without a soul, Spike was hers. Whether she wanted him as a lover or a doormat didn't matter.
He surrendered and kept walking. "I trust you. I'll always trust you. You know that."