As I'm walking off I look to the ground and notice poo. Lots of it. Some clumped, some puddled, but all on the floor in the stall.
"B, honey, is that poo on the floor!?"
"Golly ned, kid, why are you using a stall with a dirty floor?"
(silence from him)
(dawning recognition from me)
"B...that's your poop, isn't it?"