Try sleeping with Alex on Sunday night when she's at corruption 2. Opens up a new path for dialogue.
I actually just got this path a few days ago, so I know it's not broken on version 50. Make sure that Hailey isn't at the reunion. There's an alternate path that doesn't allow you to get Alex's corruption 3 if Hailey is there. You should be in the Share Bed with Alex path. Also make sure you have corruption 2 active and have Alex at love 5 by the time sunday midnight rolls around.