Dianna Agron, who plays Quinn Fabray on Glee, is on the cover of the September issue of Cosmopolitanlooking nothing like her on-screen self.  Inside the mag, Agron reveals why she stays mum on her dating life, despite rumors of a timultious (and possibly abusive) relationship with I Am Number Four co-star Alex Pettyfer and -- much more serene -- new relationship with Gossip Girl's Sebastian Stan.