"You never much cared when I chased you before." Spike knew that things had been different then; he hadn't had a soul and Buffy hadn't trusted him, thinking that he only said he loved her to try and get close and ultimately kill her, which had never been the case when if she had driven him crazy and sometimes he had thought it'd be easier if she wasn't around, but he could never actually bring himself to do anything about it, because in the end, he loved her.
As the elevator door opened on the top floor, he led her towards the door that led to the roof and glanced over his shoulder at her, but he didn't say anything; instead, he let go of her hand, opened the door and started up the stairs, knowing that Buffy's curiosity would cause her to follow him.