Were Rachel Berry’s Sins Unforgivable on Last Night’s Glee?

Last night's Glee was a refreshing return to plot sanity, but ... oh, poor Rachel. After a season of growth, she backslid a bit into the vain, jealous, selfish diva she was in season one. Understandably offended to learn that Finn had done the nasty with Santana and not told her, she went and hooked up with Puck — which even Puck realized was a bad move before Rachel did, and Finn broke up with her because of it. Rachel had come back to her new, mature-ish self by the end of the episode, but is this it for the improbable couple?