It's impossible for me to discuss this book without getting into what I would consider to be spoilers.
Remember when I called Chéri a "lovely book?" This sequel is the antidote to that. If the previous book was all about the ending of a romance between the titular character and Léa, his older lover that he is having difficulties letting go of, this book shows once and for all the aftermath of a love affair in general, and in particular one that society brings to a close.
But I don't think it's that simple at all... in fact, I think Chéri stands for an entire generation. In the first book he is spoiled, an idle rich brat who gets his way because of his money and his striking good looks. This book shows a young man who has been through a war, and is now faced with what is going to become an end to his idle-rich way of life, thanks to post-war economics, better opportunities for the "lower classes" than having to be servants, etc. Everything is changing, even his beloved Léa. Chéri becomes lost in trying to hold on to the past, but everything slips away from him - his wife, his mother, his memories. It's a sad book, honestly. But it's also frank in that it examines this malaise that probably infected an entire nation at this time. I think it has a logical end; but the logical part of it doesn't make it any less sad.
I will have to prioritize some more Colette soon.