Ok, so we all know from the Pilot episode (and also books) that Melissa is a hell of a suspicious girl, right? We all think that little miss Perfect Hastings is plodding against our prettiest little liars, but here is my theory.
Melissa can't be A.
Why? I have a very simple answer to that question.
SHE'S A GIRL.
But you already knew that, right?
What I meant was, Melissa, no matter how much evil exist in her being, she's a girl like every other on this planet. She is paranoid, confused, curious, anxious, and what's most important to my theory here, she is JEALOUS.
We all know how Ian just loved to add some fuss in Rosewood. And we also know he hooked up with Courtney DiLaurentis.
Remember how in the end of season 1, when he fought Spencer and suddenly A appeared and..well, killed him? A second before that Ian asked terrified: "What are you doing here?" which means that Ian knew A, more precisely, HE WAS ON THE A - TEAM.
And Melissa knew that he was with Courtney, so she could never be on the same "team" or whatever with him (even though she continued to be his girlfriend and all).
And what is the main goal of the A - team? That's right, REVENGE. Revenge to our four pretty little liars. Melissa is a smart girl, she would never be with Ian unless she had a plan of her own to destroy him. And when a girl has to choose between getting back to her little sisters friends or destroying her sleazy ex completely, oh, what will she ever pick?
I know what you are going to say, what about all that Spencer/Wren situation? Well, when we look this situation from another point of view, we'll see things clearly, right? And the truth is, however dreamy he might be, Wren is one slimy jerk who can't pull himself together and stick to one girl per season.
So to conclude my expose, I don't think Melissa is on the A - Team. It would've been to easy. I think she has a plan on her own, and that she will storm with it when we least expect it, leaving us, once again, completely and utterly shocked.
But what do you think? Fell free to comment (it's a forum post, for crying out loud!:D) and let me know what you have to say!
This article is taken from my blog called anylovesya.blogspot.com :)