The final episode of the series.
This is the only episode of the series in which Felix's bedroom has a window.
Felix promised Gloria he would change and she accepted him back. But he was still behaving like the same old Felix even at the wedding.
The officiator at Felix's and Gloria's wedding is played by Bartlett Robinson, who has an odd connection with The Odd Couple. He had originally worked with Jack Lemmon and Walter Matthau in The Fortune Cookie (1966), which was the first film the pair worked together on. The pair would go on to star in the film version of this series.
According to Felix, he was toilet trained at 5 months, and at 7 he was training others.