All right, sweet thing, if you want to know what I think, the truth is that they're both touched in the head. We all know Hawke was born without any wits whatsoever--hush, kitten, that's what I like about her--but Varric is only better at hiding it. He puts on a good act, doesn't he, but we know the truth of it.
It seems unlikely when you first meet them, I'll give you that, or at least it slipped by me, although I did have other things on my mind at the time. They're joined at the hip, of course, hard to miss that, but that's because their act is good enough that they've fooled even themselves. Oh, what do I mean by act? You've seen them at it, kitten--the best friends, bosom companions, true comrades and all that rot. They drink together and play cards and tell each other lies and go home at the end of the night to their separate beds because there's nothing to see there.