The Film: Star Wars (1977)

The Inappropriate: Freud would have a field day with these two.

Upon their initial meeting, Luke immediately falls for Princess Leia’s ballsy charms. He doesn’t know that the bun-donning beauty is really his long-lost twin.

In retrospect, it’s pretty gross. There’s that awkward moment in A New Hope where Leia plants a kiss on her brother “for luck”, then smooches him again in Empire to stir Han’s jealousy.
 
How They Make It Work: Have no fear, the flirty pecking is as far as it goes. Luke soon learns the truth, and Leia realises that she's loved Han all along.