<P> To keep the show 's title plausible , the show 's head writer , George Tibbles , fashioned a three - part story arc in which an orphaned friend of youngest brother Richard ( Chip , played by Stanley Livingston ) , Ernie Thompson ( played by his real - life brother , Barry Livingston ) , awaits adoption when his current foster parents are transferred to the Orient . Steve offers to adopt Ernie , but faces antagonism from Uncle Charley , who finds Ernie a bit grating , and forecasts major headaches over both the boy and his dog . It also transpires that a law requires a woman to live in the home of an adoptive family . A likable female social worker supervises the case , and the Douglases speculate that Steve might marry the woman , to make the adoption possible , but they both agree this is not reason enough for them to be married . The family also does not need to hire a housekeeper , since Uncle Charley already has things running smoothly . The family soon appears before a judge who researches the law , and determines that its intent is to ensure a full - time caregiver is in the household . With Charley meeting that role , and having had a change of heart about Ernie , Charley assents to a legal fiction declaring him `` housemother '' to the Douglas family . </P>
<P> To keep the show 's title plausible , the show 's head writer , George Tibbles , fashioned a three - part story arc in which an orphaned friend of youngest brother Richard ( Chip , played by Stanley Livingston ) , Ernie Thompson ( played by his real - life brother , Barry Livingston ) , awaits adoption when his current foster parents are transferred to the Orient . Steve offers to adopt Ernie , but faces antagonism from Uncle Charley , who finds Ernie a bit grating , and forecasts major headaches over both the boy and his dog . It also transpires that a law requires a woman to live in the home of an adoptive family . A likable female social worker supervises the case , and the Douglases speculate that Steve might marry the woman , to make the adoption possible , but they both agree this is not reason enough for them to be married . The family also does not need to hire a housekeeper , since Uncle Charley already has things running smoothly . The family soon appears before a judge who researches the law , and determines that its intent is to ensure a full - time caregiver is in the household . With Charley meeting that role , and having had a change of heart about Ernie , Charley assents to a legal fiction declaring him `` housemother '' to the Douglas family . </P>
who played chip douglas on my three sons
who played chip douglas on my three sons
Stanley Livingston
Stanley Livingston