It felt like something flew away from inside of her chest when Spike said he didn't want to leave her. Maybe she was putting too much meaning behind it, but it sounded a lot like Spike wasn't willing to give up on her, didn't want to. She knew he still loved her, but after everything they'd been through together Buffy couldn't see how. She wasn't sure how Spike had managed it, but he actually made her want to be a better person. Standing there like that with Spike looking at her in his serious-broody-mode made a lot of old feelings rush back to her. Spike was her addiction. She wasn't sure if she could stay strong if he was going to continue to believe in her like that. She wished he would just stop and leave like she asked.
"Hey, it's not my fault the forces of darkness want to kill me," Buffy retorted, but her tone was more playful and less serious when she said that. Her tone changed when Spike's did though and she shifted her weight from one leg to the other with a sigh. She couldn't look him in the eye anymore. She felt too guilty.
"Why not?" she asked him. "All I've ever done is cause you pain. You should leave. You know you should. We're no good for each other. Just go."