Uterus Knife

A rape defense.

A woman inserts a knife in her uterus with the handle facing up and the blade facing down.
This way when a man tries to forcefully take her, his penis will be stabbed by the knife.

“I’m a eunuch.”
“Aw shucks man, how’d that happen?”
“I tried to give it to Bernice, but she had a Uterus Knife.”