Does the nephew want to buy something when he goes to his uncle's house?

You can't go to my uncle's house empty-handed. This is the basic etiquette. You can buy some milk and fruit. It depends on what my uncle likes to eat, or bring some local specialties.

An uncle relationship is an uncle relationship. A man's sister can also be called a niece, nephew, nephew son, nephew, his sister's daughter, or niece.