Borgnine and Davis an unusual couple....
Davis was 9 years older than Borgnine when this was filmed. She was 48 and he 39. Nothing outrageous about that but Davis had been a star in film a whole generation earlier than he was. She was a huge star in the 1930s and he was in his first film in 1951.
Seemed unusual to me that's all. They both play a mid 40s couple with an early 20s daughter. Neither is made up to look attractive at all in this film. Davis must have gained 20 pounds and there is little passion left also.
It's just the contrast of age in a decade known for many may-september romances on film and off film.
Consider this; Debbie Reynolds was about the same age here as Grace Kelly was in High noon filmed 4 years earlier. But Kelly's husband in the film Gary cooper was 51 then. 12 years older than Borgnine in this role!