Although the exact origin of the term “Pooting” is not known, it most likely developed as an onomatopoetic expression, used by children in the aforementioned sense.
The word is defined as an Americanism and it most likely developed in the United States during the 20th century, although there are no documented cases of it in this sense.
Despite the untraceable origins of the expression, “Pooting” became a widely known expression in the United States, especially common among children or parents with little kids.
The internet, along with its capacity to make infantile memes viral, led to the spread of the term in the 1990’s and 2000’s.
It was first defined on Urban Dictionary in 2004.