When your ballsack is saggy and you stick it in her vagina when she's about to give birth so the baby starts kicking and punching at it like a punching bag from the uterus.
Right before my wife was about to give birth to my son, I performed the punching bag and he was already like manny pacquiao
by Robindaasian October 03, 2018
by Rbomb04 November 14, 2014
by EggyMemeMan October 09, 2019
by The Return of Light Joker April 01, 2009
When you punch yourself in the balls as hard as you can to kill the sperm right before you ejaculate into a woman's vagina as to avoid other forms of birth control.
"Wow, the punching bag I gave myself last night hurt, but not as bad as 18 years of child support would have."
by Kyle Willinger April 03, 2007
n. The act of taking a used condom, tying it at the end (resembling a real punching bag), and pummelling one's parter in the face with it until it breaks and the semen inside explodes on her face.
by Bryce H. April 24, 2003
PUN-ching Bag (v) - The act of lifting the penis and inflicting pugilistic damage to the testicle area.
by mr & jb September 07, 2006