He is your sister's son, so he is your...
nephew
uncle
cousin
They are married and she is his...
sister
wife
aunt
He is not her father. He is her father's brother, so he is her...
cousin
nephew
uncle
She is your mother's mother, so she is your...
sister
mother
grandmother
He is her...
father
grandfather
grandmother
They are married and he is her...
vvv
husband
They have the same parents. She is her...
nephew
cousin
sister
They have the same parents. He is her...
brother
uncle
husband
His father is your mother's brother so he is your...
nephew
niece
cousin
He is your son's son, so he is your...
granddaughter
grandparent
grandson
Your wife's sister is your...
niece
sister in law
aunt
He is your wife's father, so he is your...
father in law
grandfather
mother in law
He is her...
brother
father
cousin
She is your daughter's daughter, so she is your...
granddaughter
sister
daughter
She is her mother's sister, so she is her...
sister
cousin
aunt
Your wife's brother is your...
cousin
uncle
brother in law