To administer a royal bumming...To open a can of whoopass on one's friend/nemesis/child...To give someone a jolly good thrashing at something, e.g. a computer game, or contact sport such as killing.
"You'd better not be trying to overtake me adey. I am the king of rollcage and I shall be making bum crumble if you aren't careful. you assmunch."
"Put that child down adey, you can't bring him with you or you'll get a fresh serving of bum crumble from that police officer"