Does he have a home office or a room that only he uses? Gain access to it, bring a bunch of paper or plastic cups. Set them out on every surface, leaving no gaps between them... as you go, fill them each to the top with water.
Maybe even put something annoying in the furthest corner of the room, like alarm/timer set to go off every 30 seconds... or put his phone in the furthest corner. Or one of those fish that play music when motion is detected.
Please place one of these fish in each cup, too.
