I came into the living room and saw this...

He dumped all his Halloween candy on himself. It makes me think of those movies where a person wins the lotto or comes across a huge suitcase full of money. In their excitement and joy, they take that money, dump it on their bed and roll in it. This must be how Tanner feels after Halloween. Like he just hit the candy lotto. Although, I'm not sure if I remember the person in the movie removing all clothing except diapers before rolling in the dough.
P.S. The reason he has only a diaper on is that he had just dumped a bucket of water on himself in the backyard.
P.P.S. And don't ask me about that creepy pose he's doing. He was like that when I entered the room. I just grabbed the camera and said, "Look at meee!"