Finn is taken aback by Poe's hostility for a moment, but only long enough to realize the anger isn't directed at him. No, Poe's mad for him, and that's unexpected in an entirely different way. It makes him feel...well, he didn't think he could feel better about his friend, because he already likes Poe a lot, but--it solidifies the feeling, maybe.

"No. No, I'm not." He taps the text display thoughtfully. "So that's why you had those toys in your room."

--He just said that out loud, didn't he. Oops.