From the verb "to John". A sexual act in which a frozen or otherwise solidified poo is inserted into one's sexual partner in order to cause pleasure. The specially frozen or solidified fecal matter is often referred to as a "lovebrick" or "mudbar". The act of inserting one or more "lovebricks" anally is sometimes known as "Turtlebashing" or, more commonly, as "logging". The cold burns and sores created by these acts are oftentimes called "johnrings" or "turtlebites".
My girlfriend wanted to try something kinky, so we've taken up Johning.
My girlfriend didn't seem to like it when I Johned her last night.
Logging is very popular with American teenagers.
I could tell she was a prolific logger from the turtlebites on her backside.