"The dragon was the best part of the original trilogy. I can't wait to see the dragons they come up with for the sequels." and when they imply that the story is not so dragon-heavy, pretend you don't believe them and keep talking about how awesome the dragons are going to be.

If they try to explain what a trilogy is, explain to them that "trilogy" is the first part of a story.

If you're still together by the end of Return of the King, state that is was the worst Dungeons and Dragons movie you've ever seen on account of the lack of dragons.