Because he doesn't have a COCK.
Game of Thrones Season 2, Episode 8
Then you'll be
fucking your own bride with a wooden COCK.
Game of Thrones Season 3, Episode 8
Bronn managed to keep Shagga
from chopping off the dead man's COCK,
Game of Thrones Season 1, Episode 9
"Piss on wildfire and your COCK burns off."
Game of Thrones Season 2, Episode 5
His big COCK, I think he said.
Game of Thrones Season 6, Episode 9