it is really true. that will take place at the end of volume 5 (the manga currently on volume 2 so there's still quite a while before it happens on manga).
I'm basically certain she's just testing him because that's the kind of story it's been so far buuuuut I am totally ready for the Hentai doujin alternative version that sees things go a lot further. Also, Hime's reaction to the FF7 references were so adorable. She really is a perfect woman.