Grandson impregnated after having sex with grandmother

I was caught by my son and his wife (grandson’s father and daughter-in-law) while I was joining them at the entrance.

The grandson becomes the stepfather of the grandmother’s son.

A grandmother’s son’s daughter-in-law must call her child father.

The child born to a grandmother and grandson

As the youngest brother of my grandmother’s son,

Became a master to my son’s wife