When you are taking a shit and the water splashes back at your brown eye with the aim of a heat seeking missile.
John had to go home and shower after his morning dump turned into a devils bidet.
Water that splashes up onto your legs and, occasionally, into your anus when dropping a turd into a toilet.
“Hey man, you’ve got a wet spot on the back of your leg.”
“Devil’s bidet must have hit me.”