Funny kind of meet cute
Donat and Kerr have been apart for 3 years, each in the Navy, and effectively become different people. Having each talked themself into wanting a divorce they meet in blacked out London, agree in a very civilised way to separate and go to a pub. It's only once indoors that they first see each other and ...
As stated, funny to have a meet-cute in the last third of the film but they do it very well.