But would it be interesting?
Good question. I've wondered the same thing and am in the process of investigating the answer. Instinct is to assume that if it feels interesting to yourself, it'll feel interesting to others too, but that's not the case when put into practice. When there's a lot of intensity going back and forth between a couple, but little interaction with the outside world, there isn't much for the outside world to relate to, and so they don't care to read about it.
And yet there are successful autobiographies of couples - like
Like Colour to the Blind and
Everyday Heaven by Donna Williams. Neither is anywhere near as huge a hit as
Nobody Nowhere was, but they had enough potential to be taken on by a publisher.
You could test it by telling some of the stories you would put into the book, and seeing how people respond to them.
, and quacks like a 