george costanza's wallet
Referring to the Seinfeld episode where George's wallet was so overstuffed with junk that it made him sit at a tilt with it in his back pocket; forcing him to even it out by stuffing his other back pocket with napkins. Eventually, the wallet exceeds maximum density and explodes on the street in a shower of cash and receipts.
Hey! Don't over stuff that or it'll go like George Costanza's wallet!