The act of entering a house party, recognizing that the party thrower's selected playlist is lame, locating the source of music, and hijacking the playlist to reflect your own superior musical taste.
Luke: "Dude, I can't believe they are playing bieber right now."
Matt: "Yeah man, I'm bout to go partyjack this and play some Genuwine!"
when one engages in sexual intercourse with a drunk person they meet at a social gathering either at said social gathering or immediately thereafter.
credit completely goes to syn of EF FAME!!!
"i got a safety buzz so it would cover for any partyfucking that happened later in the night"
or
"yeah man, i went to that kegger, hit on a chick all night and then i partyfucked her"