[ words can mean a lot coming from the right person; though they're from entirely different worlds, Aerith's empathy and reassurance resonates with him. maybe it's the fact that she doesn't know much about his world that makes it feel more genuine - she's speaking only from what she knows, without any prior biases other than the experience of having lost something important to you. ]

You've got a deal - just don't be as dumb as me and try to isolate yourself, alright? Come and find me the minute you feel a frown coming on, and I'll take care of it.

[ if he's got the capacity to flirt, he's clearly feeling better... but he's not joking! he wants to return the kindness that he's shown her somehow, though he hopes it doesn't necessitate her feeling down in the dumps. ]