Return of the Jedi
Lucas' Star Wars trilogy is an homage to the movies of the 1950's, and I'm sure that while making the trilogy, Lucas used snippets from various movies that he'd seen over the years. And I think it's pretty obvious that the lines spoken between Luke and Leia "Somehow ... I've always known," are a direct copy of Betty and Derek's same quote. As well, both couples are sitting together alone, at night, in nature.
"Come with Uncle, and hear all proper!"
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