Alex is the former lover of Piper, and the reason she ended up in jail in the first place. Shes a character who seems to have genuine feelings for Piper, but at the same time continues to betray her trust whenever it will suit her needs. That dual nature is helped by the performance of Laura Prepon, who also helps give the character a funny-yet-snarky sense of humour. Shell be returning to prison in season 3, and itll be great to once again see the dynamic between her and Piper - you wouldnt bet against their affair starting up again, but they could just as easily be rivals - and also the other inmates, who likely wont respond too kindly to her presence.