Two sets of twins dating
In these stories, the brother usually wooed and wed his sister, who bore his child(ren), but on discovering that they are siblings, they are often (but not always) forced to part.
According to Tagalog mythology, Malakás ("strong") and Magandá ("beautiful"), the first humans on earth, were fraternal twins born of the same bamboo stalk.
The Goldenberg children are actually full genetic siblings, an oddity of genetics that occurs when identical twins marry identical twins (since identical twins share the same DNA).
Even the couples admitted that there are times when it becomes confusing. Locals had nicknamed the eatery the “robot couple restaurant” as they couldn’t understand how the same couple seemed to be on duty from 6am through to 3am.
is a subclass of sibling incest and includes both heterosexual and homosexual relationships.
episode, "Twin Lives" (10/9c, OWN), we meet 23-year-old twins Chelsea and Bailey. Therefore, with two sets of identical twins marrying each other, any kids they have will be "genetic siblings" to their cousins.
Their incredibly close bond has been nurtured since birth, and they see no reason to start living separate lives as they grow older.