To masturbate. This term comes from the saying "every time you masturbate god kills a kitten." To say how many times you have masturbated, you say I have killed x number of kittens.
Zeb: That's why I'm on facebook! (not to kill kittens)
Alex: How many kittens have you killed?
Zeb: I'll just say its technically kitten genocide..
Alex: Genocide means you killed enough of them so that they can't reproduce fast enough to fill the population void....... aw... I love kittens...
Zeb: KITTEN GENOCIDE I TELL YOU!!
To kill a kitten is to masterbate. Comes from the slogan, "Every time you masterbate, God kills a kitten"
Yo don't be killin' kittens in there!
Oh man she is too fine. I best go kill a kitten before somethin dreadful happens
"Killing kittens" is a very useful euphemism to those who are incapable of spelling the big word "masturbating" correctly.
The metaphorical kitten killing is carried out by proxy, courtesy of Our Lord.
Wanna watch me kill kittens?