The offspring of a sister and brother. Defines the blood relationship between the father and son. The father is both his uncle and father. Uncle comes first because no family in the right mind would tell the boy his mother's brother is his father. They would introduce the father as his uncle.
Joe: I hate you Josh
Josh: Ur mom gay!
Joe: Ur dad lesbian!
Josh: ur Grandpap a trap!
Joe: ur GRANNY TRANNY!
Josh: Ur SISTER A MISTER
Joe: Oh god how could you...
Josh: Ur son a gun Joe: *Blows up like a nuclear bomb that destroys the whole universe*