Director David Swift was greatly annoyed throughout the filming by the behavior of leading man Glenn Ford , later telling an interviewer that if Ford were his child, "I would spank him".
Glenn Ford was 17 years older than Hope Lange. Despite this age gap, Ford outlived Lange by 20 years, passing away in 2006 at age 90, three years after Lange died in 2003 at age 70. Ricardo Montalban was 13 years older than Lange, and also outlived her, in his case by 18 years, passing away in 2009 at age 88. Of the four actors portraying the two couples, Ulla Jacobsson had the shortest lifespan, passing away in 1982 at age 53.
Glenn Ford and Hope Lange were in a long-standing relationship when this movie was made.
Millie's fortune of $40 million in 1963 would be worth almost $400 million in 2023.