Let's face it, Star Wars is sexy. Depending on how far you take it, your significant other may be willing to fly with your creepy fetish. Things to exclude: losing your hand, shooting first, and crushing on your sister.
Watching and Humping
If the movie is on during coitus, for the love of God, do not lose your groove watching it. No one will be happy. Well, okay, maybe watch a little but absolutely do not quote it. (Lines like "use the force" and "don't get cocky" are okay.)
Lets say that you're lucky and you both like Star Wars enough to be aroused by it. You should still pay more attention to getting down than Leia in that bikini. Debate is open as to whether this is healthy behavior or not.
If you're freaked out by your partner getting turned on by Star Wars, just be thankful they're not watching American Psycho. I almost lost a girlfriend that way.
Having your girlfriend dress as Leia is awesomely hot and tame enough to actually ask for. Try asking her to dress as Boba Fette and see how far you get. If she will dress as Boba Fette, way to go. I think.
When I'm not making whopee as Batman, I like to dress up as Admiral Ackbar. It usually is a massive turn-off. Regardless, don't be afraid to express your inner perv and dress as whatever obscure character that gets you off.
I'm not talking about online roleplaying. Well, maybe a little bit, but no video games. I'm talking about assuming identities of characters in the Star Wars universe in order to sexually excite your partner. Dibs on Admiral Ackbar.
Popular roleplaying match-ups: Han and Leia, R2-D2 and C-3PO, Yoda and Luke, Padme and Mace Windu. Also, young Obi-Wan is pretty popular. I hear the force is strong in that one.
There's a few sexy scenarios from Star Wars you might use to liven up the atmosphere. Examples: Luke rescues Leia (creepy), Leia rescues Han (while he's blind), and Leia services Jabba and his crew as his prisoner. Save that last one for group sex.
As long as you practice safe sex, and do it with minimal creepiness, your little nerdy unit should be all right.