User blog comment:Jam7/Bizarre Love Triangle: My Predictions for DxC and DxG in Season Three/@comment-1756703-20100730223259

Look at it this way -- Courtney only turns into a vengeful "brat" when she feels like her trust has been betrayed, or when she feels like she's been seriously wronged. And when that happens, watch out. As I've said so often, she fights fire with fire.
 * In TDI, she was unfairly booted off.
 * In TDA, she was still bitter for her unfair elimination in the first season, plus she suspected that her boyfriend cheated on her with another girl.

But in TDWT, she's actually been relatively genial so far, even getting along with her supposed enemy Gwen. Why? Because she hasn't felt betrayed. She's in a good place; she got to participate in the third season from the start, she's still with Duncan, and it seems like she's enjoying herself more often (especially when it comes to the songs).

Unfortunately, that's all going to change in the next few episodes, and you know why. Given the crap she's had to endure, I honestly can't blame her for reacting the way she does. As for the severity of her reaction, I just have one-and-a-half words for you: Type-A.