(I think its by NOZARASHI Satoru) I once read a series about a brother and sister having sex. Sister gets ousted as pregnant and moves away. Years later bro and sis are married and hid from their children that their inbred. Their daughter is committing second gen incest with her (twin?) Brother. Mother/Aunt is pregnant again in the hospital and "with" her Husband/Brother while their "children" are having sex outside the hospital. Mother reveals over the phone that she married her own brother.