(all) in the family
Within or among only the members of a family or other small, intimate group. Hey, keep that in the family, will ya? I don't want everyone to know I'm pregnant just yet!
(all) in the family
restricted to one's own family, as with private or embarrassing information. Don't tell anyone else. Please keep it all in the family. He only told his brother because he wanted it to remain in the family.