Ford Madox Ford’s The Good Soldier is the classic work on the theme of appearance vs. reality in relationships. The four main characters of two couples are flawed and everything that happens in the novel is realistically ironic. I first encountered it in a 19th and 20th century English lit course back in 1970 and I would rate it as a major 20th century novel on male-female relationships.
I also highly recommend the 1981 Acorn Media DVD which was once shown on Masterpiece Theatre starring Jeremy Brett, Robin Ellis, Susan Fleetwood, Vickery Turner, Elizabeth Garvie, Pauline Moran and John Ratzenberger. The faithful adaptation of Ford’s novel was written by Julian Mitchell and subtly directed by Peter Eckersley. This remains the best-ever tv movie about Edwardian heterosexual relationships and about the falseness of modern relationships because of character flaws and agendas. Outstanding original and movie, both. (ps/The narrator is a delightful buffoon.)