My Sister Pretends to Be a Lucky Girl to Be the Dragon Concubine

The dragon priest predicted that a lucky girl would appear in the fox royal family, which would ensure prosperity for his descendants. My sister and I were betrothed to two dragon princes by the Dragon King. After marrying the prince of the dragon clan, I had nothing to do for a hundred years, but my sister gave birth to twin dragon sons with the second prince. My sister has become the daughter of destiny, and is loved by thousands of people. The prince hated me to the core and rewarded me to his subordinates who humiliated me to death. In his new life, the prince chose his younger sister as his wife without hesitation, in an attempt to seize his luck. How did he know that it wasn't me who couldn't do it, but himself.