The SSS-Class Dragon King Won't Let Me Go

I was the weakest snake shifter in my family. My fiancé wanted to end our engagement, so he gave me an iron egg and said we could marry if I hatched it. I cared for the egg like my own child. Then it hatched into an SSS-class Dragon King. Only then did my ex-fiancé realize his mistake. He came back, begging me to marry him.