My Favourite Wife - Tony Parsons

A London lawyer moves himself and his beautiful family out to Shanghai, in search of partnership and ex pat package (ie wealth). His wife doesn't settle, his child's asthma is made worse by the Shanghai smog, and he spends all his waking life at work, with clients or decompressing with new and still single colleagues.

Husband and wife realise that their des res apartment block doubles up as a "golden cage" of Shanghai's "canaries", ie the second wives (21st century concubines/mistresses).

Husband falls for one of them and starts an affair. Ignorant of this, first wife decides to return to London with child to look after her ailing father. Husband gets more involved with second wife, and eventually colleagues and first wife find out. The inevitable shit hits the inevitable fan, but they stay together for the sake of the child.

It's all a bit predictable, but the Shanghai setting is spot on, as is the world of the international corporate lawyer.

Amazon.co.uk link: My Favourite Wife - Tony Parsons