While it is a common misconception that the phrase originates from “The Simpsons”, it actually first appeared in the 1985 movie “The Breakfast Club”.
“Eat my shorts” was later adopted by the animated series as the catchphrase of Bart Simpson who would regularly drop the line as a means of disrespecting characters of the show.
According to Nancy Cartwright, the voice actor behind Bart, she would use the phrase as a prank while in her high school marching band.
Over the long run of “The Simpsons” many fans adopted the phrase, which also appeared in various other contexts, such as Futurama.
“Eat my shorts” was first defined on Urban Dictionary in 2003.
Online, many people use image macros of Bart Simpson with his pants down, paired with the captions “eat my shorts” to express their mischievous humor.