anything related to sex, especially if discussed by a fictional comic book character known as "Mister Kim" of Manayunk, PA where in the late 90's the cable porno channel was "channel 68". Also used by various members of Philadelphia bar / art / bicycle riding scene to express any and all comments related to sexual activity, and/or derogatory imitation of asian people.
"ohhhh, davey, you 68 last night? use goooood sisty-ate technique? go real slow, then fast, like piston!"
"dude, I saw you talking to that fat girl at the bar last night, you 68 that jawn?"