I believe he won't have a child simply because he doesn't want to be tied to being king/emperor longer than he has too. If he has a child the prince could possibly lose his position and people will instead push for his own child to become the crown prince. That's the whole reason for the contract with the empress/queen in the first place. To maintain the title until the prince is of age to exceed the thrown.
Then he can go do whatever he wants since the main reason for him to even being the emperor right now is that his parents died and his father begged him to watch over the prince.
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Possible spoiler.. In the later chapters he talks about a great sorceress to the princess from long ago.. so he could be (I think he is) the actual dragon/guardian of the takar family who's just doing a favor for the family.
Uhhh sorta not... the emperor/king talks to the princess about someone from long ago and how much he trusted/loved her in a way. As he's talking the princess is like well when you're in love you feel this way blah blah blah.. and he realizes he feels that way towards the empress/queen and goes on a spoiling tangent for the empress/queen.
But all that to say the story's main focus is the princess's life you're not really going to see different pov's unless something happens to the princess to trigger that.
Ch27- is the king impotent? ? Why won't he have a child????