...no? [Yes. And the fact that he's not looking at her entirely is enough to say that that is precisely the reason. They're both flopped on opposite ends of his bed and this conversation's weird because it backs Luke right into a corner.] It kind of happened and I thought it made the most sense to keep an eye on him to learn about her in case she decided to turn on you.

[So. In some fucked up way he was kind of looking out for Thalia. It makes sense to him.]