At Tony's house, when Dr. and Mrs. Bellows look out the front window to see Jeannie's sister kissing Biff... and they think it is really Jeannie who has just gone into the kitchen with Tony... you can see the kitchen door open behind them, but Tony and Jeannie closed it behind them when they went into the kitchen...
The episode's actual title is "My Sister, the Home Wrecker".
Major Healey actually calls his date "Tina" when he tried to introduce her to Dr. Bellows, but she is credited as Cindy.
For some reason the name of Roger's girlfriend is changed from Tina to Cindy.
This is Michael Ansara's final appearance on the show.
This is the final appearance of Jeannie's sister.
Barbara Eden plays Jeannie's sister for the 9th time.