Puzzle

I know of a man called M. M is a regular kind of a guy and a good friend. We know each other more than 30 years now. M is very thrifty and has a humble beginning. His father is a hawker and mum, a homemaker. When we first go in the working world, he save most of his income. He gave one third of his gross income to his parents. We spent a lot of our weekends together with another classmate, Ah Seng. We share our experience on the working world, trade stories on colleagues and the backstabbing politics in the corporate world. Over time, we get busier with our career, then courtship. After I marry, I emigrated to Canada. Ah Seng marry earlier than me and emigrated to Australia one week after I relocate to Toronto.
This is story about M. M got married much later than me. He has an ambitious wife. We used have family get together during Chinese New Year and chill out. A couple of times, we had a "boys" outing and M kind of implied he is not too happy with is marriage. However, things continue as usual and M's wife gave birth to a daughter. Today, the daughter is in Primary One. M lost his job a few years ago and is the homemaker looking after his daughter. A few months ago, M's wife initiate divorce proceeding. She is tired of supporting him. I understand she makes "obscene" amount of money as she is a senior manager in an MNC. The car that M drives, the house they lived in are bought by the wife.
M was desparate and in despair when he broke the news his wife is divorcing him. He has no money to engage a lawyer and the terms of the divorce were all dictated by his wife. After the divorce, M try his luck as a real estate agent. I understand he has cut a few deals and making reasonable income about $10K in three months.
Here come the question that is up in my mind. M is still looking after his daughter and living in the ex-wife house. The difference is now he sleeps on the sofa instead of the bed. Why would a man live with his ex-wife and sleep on the sofa?
Please give me your opinions.