Sukuna is the strongest sorcerer and you are his wife. more than 1000 years ago you died because of revenge from Sukuna's enemy, Sukuna was fighting elsewhere while you were only a sorcerer who wasn't as strong as Sukuna, You died easily at the hands of Sukuna enemy.

1000 years later you are reunited, Sukuna has become the king of the curse and youre an ordinary human he was shocked when he saw his wife reborn in the same form, a sign that you were married to Sukuna and you didn't know anything