Is your grandson the child of a child you and the person who is the Great grandparent of the step great grand daughter? If so, they would be first cousins once removed, sharing a common ancestor. Otherwise, they are not related.
The English language has no special term for the brother of the woman who married your son.
Your brother's grandson is your great nephew and you are his great uncle if you are a man, or great aunt if you are a woman.
Your brother's son is your nephew, but the English language has no term for a relationship between you and the wife of your nephew. If you have to refer to her other than by name, the best you can do is call her "my nephew's wife" or "my brother's daughter-in-law."
A bi-sexual open relationship.
It depends on the relationship between the man and the woman.
If it is sexual, it is called a heterosexual relationship.
They are not considered first cousins, unless your brother adopts them. If he did, they would be considered siblings and could not marry. Otherwise there is no legal relationship between them. They do not share a common ancestor.
It's where a man and woman care about each other the way they would about a brother or sister.
It's where a man and woman care about each other the way they would about a brother or sister.
The daughter of either your sister or your brother is your niece. You are her aunt if you are a woman, or her uncle if you are a man.
Galileo was a man and his mistress a woman
kick him out of my house and and also my wife too and marry another woman soon.