Esther Williams was pregnant during the filming of this movie.
A specially built, one-of-a-kind piano had been used during the early filming, but halfway through production it mysteriously disappeared from the set. Metro boss Louis B. Mayer was very upset at the lack of security and the increased production costs this would mean. Red Skelton told the studio head that he had an identical piano at home and would be willing to rent it to the studio. Mayer didn't believe him until Skelton drove him to his apartment to see it. An ecstatic Mayer offered $50 per diem for its use, but Red held out for $1000 a day. Faced with the prospect of keeping production waiting while a new one was built to order or reshooting the earlier scenes, Mayer capitulated. It never occurred to him that Skelton had stolen it with the aid of stagehands with whom he split the money.
In a 1999 interview, Esther Williams recalled that she and Ricardo Montalban were originally supposed to sing Frank Loesser's song, "I'd Love to Get You (On a Slow Boat to China)" in this film. But MGM's censors rejected the song as too suggestive. (Strangely, they interpreted "get" as "have" in a sexual sense.) When Williams asked Loesser for a new song, he offered the now-classic, "Baby, It's Cold Outside." The MGM censors offered no objection to it, even though Williams thought the lyrics were even more suggestive than "Slow Boat To China".
In this film, Esther Williams plays a swimsuit designer. She later copied several designs from this film for a line of swimwear that she would create.
When Frank Loesser's "Baby, It's Cold Outside" was nominated for the Academy Award for Best Original Song, other songwriters protested because Loesser had originally written it in 1944 as a duet for himself and his wife to sing at parties, and they argued that it should not therefore be counted as an "original" song. But the Academy ruled that since the song had never been performed PROFESSIONALLY before it appeared in the film, it was therefore eligible, and it went on to win the award.