Addison Derringer is going to be the bane of the Liars' existence up until the end it looks like. The Alison DeLaurentis mini-me is not nice. She also appears to be a pawn in A.D.'s endgame plans, which is probably why Addison was texting Jenna on Pretty Little Liars this week. Or was she? Everyone is so shady on this show, that it's always hard to figure out who's plotting what and who they're working with. This much we know so far into 7B — Jenna is definitely working with A.D., if she's not A.D. herself. (Running theory: Paige is A.D., for Athletic Department head, since she and Jenna both hate Ali, and was able to assist Addison in her mission this week. Whaddya think?)
Addison, though she has the right initials, is not A.D., but she might have been texting Jenna the details about how to take Emily down, since it was Em's turn at The Game. There were a lot of things going on in the plot of "These Boots Are Made For Stalking." To start, Addison was given all the pieces necessary to craft a malicious lie about her swim coach. This would be the only reason that Jenna and her were — allegedly — texting at The Brew. Working out the kinks of her accusation story and getting the right pictures to make it work.
However, the twist at the end was that someone had been stalking Addison, too. Or at least was smart enough to get the security footage from the alley behind The Brew to catch her skipping practice and smoking pot in a car with her boyfriend. That could have been Jenna or A.D. Or maybe Addison and Jenna set that up, too, so that they could have a way to make Emily stoop to blackmail, or think the whole ordeal was over. Anything is possible at this point.
Either way, Jenna is definitely up to no good at all, as usual. Except now she comes with bodyguards. In addition to possibly directing little Addison, Jenna also managed to craft the most ridiculous (yet pretty convincing) story about being scared of Noel Kahn at the police station and somehow copied the dress that Hanna was going to give to Katie, her new client. Jenna was singlehandedly messing with Spencer, Emily, and Hanna all at once this week. That's A.D. level trouble.
PLL viewers will have all their questions answered soon. So maybe we shouldn't worry too much about who Addison is texting, but rather be asking what exactly Jenna is up to in Rosewood and who else she has working for her.