Want this question answered?
Nothing really. There is no blood relationship between the two.
father
If your father's brother's niece is really your father's brother's wife's niece, then there is no genealogical relationship. Otherwise, she's either your sister or your first cousin.
Your father's brother is your uncle. You are his niece (if you are female) or his nephew (if you are male).
If your mother and her brother share the same parents, then her brother's father would be considered your grandfather
There is no direct relationship between your father's brother's nephew's cousin's former roommate and you. They are an indirect connection through various family members and acquaintances.
Your father and your aunt are siblings (brother and sister) The grandchildren of siblings are second cousins to each other.
your
Your father's brother is your uncle. You are his niece (if you are female) or his nephew (if you are male).
It's the narrator's son.
Your Grandad! yeah your grandfather
Your brother's father-in-law is not related to you unless you and your brother married sisters from the same family. Then he would be your father-in-law, too.