From: GANON1025 | #016
I felt Half Blood Prince did have a weird tone to it at first, everything seemed a little too cheery. It picked up in the second half, I thought.
Goblet of Fire also had this weird thing where Ron and Harry were mad at each other, but it wasn't really explained why. And then the reconciled and THAT was also not really explained.
I think Ron was jealous of him because he got picked for the Triwizard Tournament despite him not being a 7th year student and therefore getting a ton of attention. Ron also acts like a jerk to Hermoine at the Yule Ball because she went to it with Viktor Krum.
edit: also, I remember in the movie there was a scene where it's implied that Ron grabbed a French girl's ass or something, which, as far as I know, isn't in the book at all.
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