Well, if it were infallible, we wouldn't be intuitive, we'd be psychic.
I was thinking about this earlier, and it might be a mistake for any of us to read too much into what we've been shown in this regard, since what we're essentially viewing is a male writer's direction to a male artist to depict, in a suggestive matter, two women engaged in a [X] type of relationship, where [X] is whatever the heck is really going on between them, the subject of much debate. So for me to apply gender-specific 'intuition' (shame on me for invoking it, I suppose ;) ) is probably a mistake, since we're not viewing a real relationship, nor even two actresses depicting a real relationship, but an artist's interpretation of same, and his interpretations are colored by his identity as a recently married, homeowning part-time male webcomic artist, which may or may not depict [X] the same way in which my own intuition would interpret an ideal depiction of [X].
So, this is my wordy way of saying: I STILL am not convinced Wanda/Jillian's relationship is, essentially, a romantic one, but for me to put too much stock in an intuitive guess based on my own gender perspective as to what is really going on is likely a mistake on my part. Boo, me! :P