Found: Book about couples cited in another book

I am looking for a book cited in another book, but unfortunately I only remember bits and pieces of both.
The cited book is about some couples (I think three) and their relationship, and it is cited by the other book (whose subject I can't remember) in a passage that roughly says "The man of one of the couples had a shed ,or a garage with plenty of tools that he always kept clean and in order. He was basically always prepared but never started any project." The author of the latter says that the "couples book" is one of the best he/she has ever read on couples and felt very emotional when he/she read it.
Can you help me finding both books?

I thought it might simply be Couples by John Updike, but that appears to have ten couples rather than three.

I also thought about that, but it doesn't seem to have that "vibe" that the book which quoted it seemed to give it.
Have you read it? Does it have any paragraph about a man with many tools that he never uses?

I found it! The book is "Crossing to safety", cited in "Test-driven development".

Crossing to Safety. I didn't recognise it from the description, but it's an absolutely lovely novel and I can definitely recommend it.