Triangle Troubles is the 22nd and final episode of Season 3 of Three's Company, and the 53rd overall episode of the series. Co-written by Al Gordon and Jack Mendelsohn and directed by Dave Powers, it first aired 15 May 1979 on ABC.
Summary[]
Jack goes out with Debbie. He thinks she is an "old-fashioned" girl and doesn't want to tell her that he lives with two girls. When he invites Debbie over to his apartment for a cooking project, he has Janet and Chrissy take off as he believes Debbie wouldn't approve of a man living with two girls. What Jack doesn't know, however, and what Debbie is reluctant to tell him, is that she lives with two other men.
In the midst of all this, Reverend Snow, Chrissy's dad, pays an unannounced visit. He winds up adding his input on the situation, when the truth is revealed to everyone about each other's living arrangements, not only between Jack and Debbie, but also to Chrissy and Janet's dates.