Did Swallow and Yongqi get married in Princess Pearl? Why marry Xin Rong first? Isn't the theme "happiness"?

Swallow and Yongqi are getting married. Because of the photos of their wedding, Xinrong got married for filial piety, and Princess Hedo threatened to die. Yongqi was helpless and married Xinrong first. The plot of the TV series is not perfect, so we are not in the mood to watch it. I think we will still feel happy after reading it ~ ~