Leviticus 18:11-13

¹¹Thou shalt not uncover the nakedness of the daughter of thy father's wife; she is thy sister by the same father: thou shalt not uncover her nakedness.

¹²Thou shalt not uncover the nakedness of thy father's sister, for she is near akin to thy father.

¹³Thou shalt not uncover the nakedness of thy mother's sister, for she is near akin to thy mother.