Man soll nicht mit der Liebe spielen

While making this film, Frank Sinatra took an almost immediate dislike to Doris Day's husband, Martin Melcher, thought that Melcher was using her to get ahead in the movie business and tried to convince Day of that fact. After Day refused to listen to Sinatra's advice, he had Melcher banned from the set. After Melcher's death in 1968, it was discovered that he had squandered all the money Day had earned during her 20-year film career.

When Laurie asks Barney why he doesn't have any plants in his window box, he says because they use up all the oxygen. People commonly conceive that plants actually use carbon dioxide and produce oxygen, and this has therefore commonly been regarded as a goof. However whilst a plant is a net producer of oxygen, it does this mostly during the day, whilst it is photosynthesizing, at night time plants do indeed use more oxygen than they produce and this can affect sleep. Barney's explanation is therefore quite sophisticated and indicates a focus on the night time.

Featured in The Doris Mary Anne Kappelhoff Special (1971)