When your fucking your girl bent over a folding table on the range, while having a thumb in her brown eye and having .50 cal balanced on her head, you fire the .50 as you ejaculate and when you explode the rifle also explodes... in your face almost killing you and your partner in the process
A sex term made relevant by Kentucky Ballistics.
"Put a thumb in it"
Right before a female has a squirting orgasm, stick your thumb into her vagina to prevent fluid loss.
"Man my girl is a squirter so i had to give her the ol' Kentucky Plug last night to save the sheets."