I think it's Mona or Mellissa (for some reason lol) If it's Ezra I'll die! But remember when Ezra saw Arias text from A and was like " Who's A? Who else knows about us? B and C?" They make it so hard to try to guess ourselves..
Just to be on topic. Did you see the rumours that Demi was going to play Courtney on there? I just LOL'ed
If its Mona I'll be disappointed since its too effing obvious