When snow fell in the capital in June, he understood that something was going on. It basically meant that the door to enchantment would open soon, and the Phoenix Girl would come into being ahead of time. At that time, Ruxue was going to be recognized as the real Phoenix Girl, who would be respected and admired by tens of thousands of people.
At that time, Ruxue would be as important as the throne, and many people would become ambitious.
Wars, or thrones, rebels, what mattered the most was that they needed to have the Phoenix Girl's support. In this way, they could keep the imperial blood.
So he should not waste any more time and needed to have a lineal child with Ruxue.
He was not very concentrated when he was in Qianqing Palace. That was because Junyi's messenger told him what happened in the court and he understood that Ruxue held his destiny, not his father.
The power of the throne was much smaller in front of heaven's destiny.