Here's my contribution to the game of gross tag that some of my blog friends (including Coaster Punchman) are enjoying (or not enjoying, as the case may be).
Years ago, when we were kids, my brother dog-sat for the neighbors while they were on vacation. The dog was nervous when the neighbors were gone, and would poo in her indoor concrete-floored kennel instead of going in the yard, as she would when the family was home.
My brother walked into the dog's inside kennel (linked to an easily accessible outdoor run) to find a big pile of sloppy poo, which he would then move to gaggingly clean up, and inevitably throw up in the middle of. (He's always been quite squeamish. Even listening to descriptions of gross things incites his gag reflex. I, on the other hand, can shovel horse poo and change diapers all day with no problem.)
The dog (whose name was Dandy - somehow this is important to the story) would then happily lap up his puke, before he could shakingly run over to clean it up. On each following visit, it would be the same thing all over again, except, of course, after the first time, it was actually his vomit she was pooping each visit, which then inspired his next round of puking.
We still laugh disgustedly at this sometimes, and refer to it as "the circle of life."