The Awful Truth (1937) on Netflix

Although they still seem to love each other, New York sophisticates Lucy and Jerry Warriner don't feel they can trust the other any more based on what appears on the surface of their marriage, despite each vowing that what they state, contrary to appearance, is the truth. As such, they decide to get a divorce, they, however, still needing to see each other based on visitation rights for Mr. Smith, aka Smitty, their pet terrier. With two months to go before the divorce becomes final, Lucy doesn't seem too anxious to replace Jerry with any other man, until she meets Dan Leeson, an Oklahoma oil baron, who she agrees to marry, largely as he represents the antithesis of Jerry. And based on that mistrust in their marriage, Jerry gets engaged to snobbish socialite Barbara Vance. However, each eventually comes to the conclusion that they still love each other and try, without directly saying so and without the other knowing, to get back together. The questions become whether they will come to this conclusion at the same time, and if so if it will happen before they are no longer man and wife in sixty days.