King Uther is not ignorant, nor is he stupid. He sees and knows more than people think he does. King Uther is no fool. He knows precisely what is going on right under his nose. Arthur does not think that King Uther sees the looks he gives his man-servant. Arthur does not think that King Uther knows about the forbidden kisses his son and his man-servant share in secrecy in the corridors. Arthur does not think King Uther has people who has seen the Prince and his man-servant in the corridors at night, lips fused together passionately, hands grasping each other desperately, their moaning echoing in the night. Arthur does not think that King Uther knows with whom the man-servant Merlin truly spends his nights with.

Arthur does not think his father knows. But he does.

King Uther is not ignorant, he knows what goes on in his castle.

King Uther is not ignorant, no. He just chooses to ignore what is right under his nose. King Uther chooses to ignore because he knows that one day Arthur will realize, all by himself, that this ridiculous crush will lead him absolutely nowhere.