[There's a frown at that and the many things it could imply.]
I don't care what ya do t'each other. Jus' don't kill her. [That wasn't entirely true, but he wasn't superman either. He knew he couldn't be everywhere at once or stalk her everywhere to see to it Spike didn't hurt her. She was the Slayer for crying out loud and if she weren't as strong then neither was Spike. They hadn't killed each other yet.]