The act of using a high powered, high caliber slug to cap or blow ones genitalia off of there body in an act of rebellion against a figure of power or authority who does not wish to comply with requests or demands of the one blowing his junk off.
Mitchell: mom i am going to BLOW MY JUNK OFF if you dont pay 3 more months subscription to WOW!!!
In reference to the act of giving birth: Blowing out your junk depicts the damage done to the female genitalia by the act of squeezing a baby through a small hole. Past tense: Blew out said junk