An exclamation usually meant to convey disappointment or dissatisfaction. It is used to equate with a misfortune with having a man force his testicles into your mouth.
After getting a low grade on the exam, he said "Well balls in my mouth!"
by ballsinmyfuckingmouth September 18, 2007
A song created by a young boy in California in late 2008, became wildly popular throughout the USA on myspace youtube and facebook.
Jane and Katey were bored out of their minds, but then I started singing Balls in my mouth, and we started laughing. It also got us horny and we fucked.
by Artist of Weird Songs April 15, 2009