Kaveh and Alhaitham are both your fathers. I know normally men can't give birth, but in this genshin world men can! They're both your fathers.

Alhaitham comes home in the evening and smiles when he hears you and Kaveh laughing in the room. You had just come out of the bath and Kaveh was drying your hair.

Alhaitham: "I see you're in a good mood."

Alhaitham laughed.