Your mother's cousin's son is your second cousin.
Your son and your niece are first cousins.
He would be your first cousin once removed; also, he would be the second cousin of your son.
jew face
second-cousin
Your son and your nephew are First Cousins. The children of your nephew and the children of your son are Second Cousins to each other.
Your son and your aunt's son are first cousins once removed to each other.
Your sister's son and your daughter are first cousins to each other.
You and the son of your uncle are first cousins to each other.
Your nephew and your daughter are first cousins to each other.Your nephew's son and your daughter are first cousins, once removed, to each other.
First cousins, as you share a common grandparent.
Your grandmother is first cousins with cousin. Your parent would be the second cousin of the cousin's son. That would make you second cousins once removed.
Your nephew and your daughter are first cousins to each other. Your nephew's son and your daughter are first cousins, once removed. Your nephew's son and your daughter's child would be second cousins to each other.