french vasectomy
The act of inserting a lit cigarette, lit end down, into the tip of a man's penis, down his urethra. The idea is that this act will render the man infertile, like a vasectomy.
"I was getting head from this French broad and she refused to take her smoke out of her mouth. She knew what she was doing, but I was still worried she might try to give me the ol' french vasectomy."