Likely it was payback by Milhouse for Bart convincing Lisa to dump him after they graduated from high school. 
They’re on 16 already!?
I lost count around 12.
Refresh my memory: how did he betray him?
With betratal. As I recall, it was non-specific.
They, the future religious nuts, did not specify. Only that Bart was betrayed by Millhouse and died when he was pulled apart by snowmobiles.
Ohhhhhhh. I was marveling at the visuals in that scene and didn’t pay much attention to the dialogue. Thank you.
I just got back from vacation and I watched the last two week’s episodes (all four) in one sitting.
They were pretty darn good! I was terribly underwhelmed by this season, but at least they ended on a high note. One disappointment was that they didn’t do a three segment “Simpsons take on” episode (e.g.- Fairy Tales, History, the Bible, Literature).
Those are usually among the season’s best.
I want to see Simpsons take on the Movies (LotR, Star Wars, Shrek, etc.)