Mr. Peabody and the Mermaid - 1948

As told to a psychiatrist: Mr. Peabody, middle-aged Bostonian on a break along with his wife in the Caribbean, hears cryptic, wordless singing an uninhabited rock inside the bay. Fishing in the vicinity, he catches...a mermaid. He falls deeply in love with her and, though she has spoken speech, takes her home. Obviously, his wife won't believe that thing at the bathtub is anything but a massive fish. Predictable complications follow quite tame fashion.