Mr. and Mrs. Smith (1941)

This is really a straight ahead romantic drama that I think is supposed to have comic elements, but really, when you get right down to it, most of them fall pretty flat, at least in the 21st century.   Very unlike most of Hitchcock's work, and I am not sure, having watched this, that I would have appreciated his sense of what marriage is and should be.
Mr. and Mrs. Smith discover three years into their somewhat volatile marriage that their marriage is not exactly legal.  It seems to me that in the early 1940's this would have been a big deal, but the whole living in sin thing seems to be shrugged off just so long as they get married as soon as possible.
Well, there is the rub.  The Smith's routinely have histrionic fights that when married there is only one real resolution for, but when that relationship is in question, leaves room for bad behavior and misunderstanding.  The end is very clear from the beginning, but getting there takes quite some time.