Clark is starting to piece things together as well. Sam and his brother (Dave? Dan?) are pretty heavily involved in situations clearly weird and unusual. Lana's told him about the vampires, which obviously didn't freak Sam out that much, but not about Isobel, and she's hesitant about doing so. That means she thinks Sam won't take it as well as he did her being infected with alien rabies (although Clark doubts she explained it quite that way).

She loves him, and Sam's biggest concern is protecting her. If Clark could get headaches, he thinks he'd probably be getting one right about now. Calling this 'familiar' just isn't funny anymore.

Clark lowers his head and prepares to tell her something they've never really talked about. A long list, yes, but he thinks this is fairly relevent. "Lana, when we broke up a few weeks after my dad died, I did it because I thought I was protecting you. I couldn't put you at risk without you knowing about me, and ...I couldn't tell you. So I think I have a pretty good idea how scared Sam is about doing the same thing."

There's a hesitation as he hazards a glance over at her. "The difference here is he's starting to tell you about his life, whatever it is. I don't think he'd do that if he didn't care, or if he didn't want you around." His gaze returns to his hands in his lap. "You don't let people in if you think you're going to have to push them away."