If a Mother accidentally got pregnant by his biological son and they had a twin(boy and girl), how is the son and the mother related to the boy and the girl? Your thoughts?

A mother sleeping with his own biological son is a taboo in many cultures and societies across the globe. Bear in mind, this is a provocativedebate.com question where individual's brain is challenged to sway and win the debate at hand. But, event of this magnitude should be carefully handled in a granular form for people to understand. There are many questions that arise from this debate question: Why would a mother sleep with his son and vice versa? Now, we are locked up in a complex situation of defining the relationships between the twin and the mother and her son.   First, the mother is the twin biological mother and her son is their biological father. But it gets more interesting, their mother is their biological grandmother because their father is her son. Now, more revelation; the twin father is their own big biological brother from the same mother. If there are other sibling in the picture, they will be classified as "aunts and uncles".....what a world! Your thoughts? Welcome to www.provocativedebate.com.