<Snipped quote by Prince of Seraphs>
Didn't look like flirting to me.
But then, how would any romances ever come to be in any stories if the author didn't have their own characters interact?
Prince, characters in Fire Emblem talk sincerely to one another all the time, even in C-supports.
That's stories with one author not twelve.
C-supports only occur after the characters have been in battle, after they know they can trust the other. Aside from being introduced Gaius and Lilith have never exchanged words. I don't know anyone that talks that sincerely with someone they've just met unless there flirting. But whatever it's not really important since I'm the only one that sees it like that.