Pulling a Skywalker

An act in which a person very nearly enters into a sexual relationship with someone who, unbeknownst to them, is a close relative, ala Luke and Leia.

Hey, it happens. You can also say "Pulled a Skywalker", as in, "So-and-so almost Pulled a Skywalker with so-and-so."

For example:

Henry: "'Sup, Jay. Man, did you hear about Mike?"
Jay: "Naw. What happened?"
Henry: "Well, apparently that hot blonde chick he was going out with the past few weeks... was his first cousin!"
Jay: "WHAT??!!"
Henry: "Yeah! Dude almost got caught Pulling a Skywalker with his own cousin and didn't even know it!"
Jay: "Hahaha! Man, Mike's lucky the worst thing they did was make out a few times!"