second family

plural second families

1. Alternative letter-case form of Second Family.
2. a married man’s mistress and her children.

   We have precedent for two opposite social attitudes toward second families, as they were called before legal second families through sequential marriage became so fashionable.

   1984, Judith Martin, Miss Manners' Guide to Rearing Perfect Children

   1 more example

   The children in these families often only grasped to full extent of a paterfamilias’s perfidy at his funeral, when they would discover, standing at the graveside, a previously known unknown second family, complete with second widow, grieving children and claims to the estate.

   2009, Michela Wrong, It’s Our Turn to Eat: The Story of a Kenyan Whistle Blower

1. The family of the Vice President of the United States.