Une petite femme dans le train (1932)

Sophisticated romantic comedy of suspicious husbands, straying wives, handsome lovers, with various misunderstandings thrown in for good measure. (Including a gender-reversal of the old Pirandello plot twist from "The Late Mathias Pascal" of the protagonist changing identities after supposedly perishing in a train wreck.)

Unfortunately the movie Une petite femme dans le train is not yet available on HBO Max.