What what relation is your mother's sister's son to you?

Answer 1

Your mother's sister's children, sons or daughters, are your first cousins.

The children of first cousins are second cousins to each other. That is the relationship between your children, or either sex, and your first cousin's children, of either sex..

Answer 2

Your mother's sister is your aunt.

Any children she has are called your first cousins.

When those first cousins have children of their own, those would be your second cousins.

Answer 3

First cousin, once removed.