It seems that the King of Brobdingnag shows affection to Gulliver by allowing him to speak of his own government and listening attentively.
As per Sparknotes.com, the king converses with Gulliver on issues of politics, and laughs at his descriptions of the goings-on in Europe.
He finds it amusing that people of such small stature should think themselves so important, and Gulliver is at first offended. He then comes to realize that he too has begun to think of his world as ridiculous.
The King criticizes England and English politics as “odious vermin” which angers Gulliver. However, it is fundamentally one of the morals.
The king refuses Gulliver’s offer of the secret of gunpowder without a second thought, not because the Brobdingnagians have superior technology, but because he is horrified by the potential moral and physical consequences of gunpowder.
Most preindustrial societies would treat gunpowder as an achievement of high order. But the king indicates that he feels it would be better to live where violence and destruction are minimized instead of exaggerated.
Gulliver’s inability to understand the king’s position—he sees the refusal as a weakness in the king’s understanding—illustrates how the values of a violent society are deeply ingrained in Gulliver.
Learn more about Jonathan Swift's Gulliver’s Travels by checking these key facts at Sparknotes.