The act of masturbating while staying as a guest in someone else's home. Particularlyentertaining if it is in the home of someone you do not like.
Harper: "Hey Chuck, I'm going home tomorrow, so you can have the room to yourself."
Chuck: "Thanks man, but I don't need it."
Harper: "You sure? I've been around all week."
Chuck: "I'm good bro, I guesterbated in JJ's room last night while he was asleep."
Harper: "Awww man that's dirty, wish I woulda thought to do that."
The act of pleasuring oneself via the most ridiculously unnecessary piece of TV drivel since The View. It is most often obnoxious and somewhat obscene to non-Gleeks who cringe when hearing one of the overwrought mashup monstrosities so popularized by the show.
My roommate was gleesturbating all last night because he "needed to catch up for the next season". If I have to hear that shitty version of Golddigger one more time, Im'ma cut a bitch.