I agree with Annie. Of course it always takes two. I did not mention that extra because I thought adult people have enough brains to know that.... well, I might have been wrong there.

The matter remains that he is unhappy and she does not care, whatever there was before, and whoever is to blame for it.
I tried to point out that whatever we say will not make a difference to the whole situation, and whatever we say might not be of use.

Counseling might be the best way, communication between them both is vital, and taking it out by using people´s arguments from an internet forum will not work.