Marry Vampire King After Rebirth

After the great war, an agreement was made: whoever gives birth to a hybrid heir first will seize power. In my past life, I married Jax, the werewolf heir, and bore him a hybrid son. My jealous sister burned us alive. Now I'm back on the day the alliance is sealed. And she's already warming his bed. But what she doesn't know is that Jax is brutally cruel to his mates.