I remember reading the book and going, "What? Ron is jealous of Hermione and Harry? God, this character just keeps getting more and more useless and annoying"

Mostly because, in the books, the last bit of Harry-Hermione innuendo happened... what, book 4? She kissed him on the cheek once.

So, yeah- Evil Artifacts aside, that particular event was so obviously off-base that it almost ruined the locket scene for me.

Playing up some sexual tension between Harry and Hermione, even if it's just a red herring, hopefully makes that later scene ring true.