Blue balls is a slang term for the condition of temporary fluid congestion (vasocongestion) in the testicles accompanied by testicular pain, caused by prolonged sexual arousal in the human male without ejaculation. The term is thought to have originated in the United States, first appearing in 1916.lue balls is a slang term for the condition of temporary fluid congestion (vasocongestion) in the testicles accompanied by testicular pain, caused by prolonged sexual arousal in the human male without ejaculation. The term is thought to have originated in the United States, first appearing in 1916.