The child calls me aunt, what is our relationship?

The relationship between aunt and nephew. When a child calls his aunt, that child is the child of his brother or younger brother. I also call my child's nephew (or niece). A child can also be a cousin's son or a nephew (or niece). A brother or cousin's son is a nephew, and a brother or cousin's daughter is a niece. The relationship between a child named aunt and himself is a nephew.