[Eddie's not generally in the habit of making promises, particularly when he knows he might not be able to keep them. Getting someone's hopes up and then shattering them has never been his thing. It's just easier to avoid putting himself in that situation.

So when he says he's not going to leave, he's actually surprised by the realization that he means it. He hadn't actually said the words, but they're just a formality at this point. There's still the question of whether or not this is all some big elaborate hallucination or something, but until that turns out to be true, he can at least make an effort to stick around for as long as she wants him to.]

That's a good sign, right?

[Or maybe it's just wishful thinking. Eddie's lost count of the number of times he'd wished for the chance to see her again.]

Okay... But I should tell you- If I wake up some morning and realize you're gone again, I'm gonna be in such a bad mood.

[It's an admittedly terrible joke, mostly meant to lighten the mood a little.]