I know. Somehow, I've always known.

Luke: If I don't make it back, you're the only hope for the Alliance.
Princess Leia: Luke, don't talk that way. You have a power I don't understand and could never have.
Luke: You're wrong, Leia. You have that power too. In time you'll learn to use it as I have. The Force runs strong in my family. My father has it. I have it. And... my sister has it. Yes. It's you, Leia.
Princess Leia: I know. Somehow, I've always known.

This exchange always bothered me. Really you always knew? That's the best you could come up with? Let's recap what's happened with these characters through 2 and 3/4 movies:
1. Luke salivates over her since seeing her hologram in Obi-Wan's cave.
2. An awkward love triangle forms with the two of them and Han Solo that persists until the end of the second movie when she clearly picks Han.
3. Most important. She open mouth kisses Luke to piss off Han.

So, if you're Luke, don't you immediately go find somewhere to throw up and take a 6 hour scalding hot shower when you get this news? You huddle in a corner in the fetal position trying to get clean and purge all the horrible fantasies you had running through your head about your... sister. Then you tell her, and she gives you, "I've always known." Then why did you put me through all that shit for 2 movies you manipulative bitch? Excuse me while I practice using the Force by throwing you against a few trees.

This is what I think about when I drive to and from Hialeah twice a week and end up getting stuck in traffic.