Continuity mistake: By this episode, Mr. Drummond has already remarried Maggie. Maggie and her son have moved in and Arnold and Sam share a room, where Willis has a room elsewhere. In this episode, there is no mention of Maggie or her son. Willis is back to sharing a room with Arnold. In fact when its decided that Charlene will stay, Arnold makes a joke about the bathroom saying that Kimberly won't be the only girl in the house (what happened to Maggie?).
Diff'rent Strokes (1978)
Episode list - season 2
Starring: Conrad Bain, Todd Bridges, Dana Plato, Gary Coleman
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Suggested correction: Season 6 was plagued with episodes being aired out of order. "The Houseguest" was actually the 12th episode produced (production code 612) and comes before The Wedding episodes (production code 620 and 621).
Willis Jackson: Arnold's always under my feet. I'll never have any privacy until he gets married.
Arnold Jackson: Married? On MY allowance?
Trivia: Arnold is in court and the judge asks the family how they know him. Right after Mr. Drummond says "I'm his father", Willis says "I'm his brother" and puts emphasis on "brother." The reason for this was revealed on a blooper program; in an earlier take, just after actor Conraid Bain said "I'm his father", actor Todd Bridges blurted out "I'm his son."
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