What is Bum Jack?
1.
The act of stealing something through burglary or mugging. Perpetrated by a homeless person.
Sam: Dude my backpack is gone; I left it in the park and now it's not there.
Matt: I bet you got bum jacked, there are hundreds of 'em in that park.
or
Matt: Jesus christ!!
Sam: What?
Matt:I just lost my wallet to a bum!
Sam: Dude you just got bum jacked!!
See
2.
the exercise of anal sex with one partners arsehole masturbating the others penis.
After we sucked each other off i gave the stud a bum jack he would never forget
