I think it's an unwritten Law of the Universe, that dads must complain daily about how bad their feet hurt. Not sure if the weight of being you dad is what does it, or if he's hinting for a foot massage from mom, but there is a solution.

For this Father's Day, think about hitting dear old Dad with a pair of Dearfoams slippers. A legendary maximum comfort favorite of athletes and celebs like Vince Young and Ray Romano, they are also the Official Footwear Sponsor of the World Series of Poker, keeping the players, dealers and even the ESPN camera crew feeling more relaxed. (And if you want to win Dad a $10,000 seat to the WSOP, go here for details.)

The original foam-cushioned slipper created in 1947, Dearfoams feature a multi-density cushioning system to keep Dad's dogs comfortable, and higher grade fabrics (in the classic plaid all dads love), that can stand up to his constant late night shuffling to the kitchen for midnight snacks.
$32
Dearfoams.com