He would be your first cousin once removed.
Your son would be the uncle of his brother's son.
Your mums brothers sisters roommate flatmates sisters brothers mothers son.
There is 2 answers your mothers brothers children or your dads sister;"s children
your second nephew
He would be your first cousin once removed; also, he would be the second cousin of your son.
Mother's grandson as regards her daughter is either her (daughter's) son or her (daughter's) nephew.
your cousin
They would be cousins, once removed.
Your mothers sister is your Aunt
Yes, she did. She had the relationship of a mother that a mother has with her son. As most mothers do.
If your niece's is by your sister but the brother is by your sisters new husband & another woman there would be no blood relation. If not then he's the nephew
Hades and Zeus are brothers; Hercules is a son of Zeus and, as such, a nephew of Hades.