You think that Glee's emotional Season 3 finale, Episode 22: "Goodbye" is going to be hard to watch? Just imagine how tough it would have been for the actors to film it! In this teary sneak peek video, the cast gives you a behind-the-scenes look at filming one of their final numbers of Season 3. Everybody is crying, but Dianna Agron (Quinn) seems to be having a particularly tough time. We just hope she's not having to say goodbye for good!