As hard as it is to believe, no one had ever uttered the phrase "sucks balls" on the Late Show until Louis C.K. did it last night, while describing his feelings about Letterman leaving the show.

Thanks to C.K.'s brave pioneering, the door is now open for incoming host Stephen Colbert—who Louie was careful not to accuse of ball-sucking—to say "sucks balls" as often as he wants.

In other news involving Louis C.K. and genitals, this is a supercut of the many, many dick mentions on Louie:

[H/T Death and Taxes]