At 6'2" and 200 pounds, John Mellencamp's son coulda done a lot more damage then he did when he and his dad got into a brief altercation recently. Bad timing for John, who was booked for a series of appearances promoting Ghost Brothers of Darkland County, the musical he and author Stephen King collaborated on. Sporting a black eye during his visit with David Letterman, the elder Mellencamp said, 'My son and I had words and he got in a punch and I didn't.'