Yep, my parents have been separated for the past 10 years, but they're still married largely due to the tax benefits, their mutually owned properties, and the fact that my mom has great health insurance that my father would lose if they legally divorced. My father also has a neat little life insurance policy lined up that will greatly compensate my mother if he passes before she does. They also save lots of money being on the same phone plan, car insurance plan, etc., but they really quite dislike each other and barely speak unless it's financially related (usually during tax season, lol). My dad even has a girlfriend, and my mom is very happy that he found companionship with her, so one could hardly consider it cheating. It's a weird setup that most people don't understand, but it's been very financially beneficial for them. It definitely happens more than people think.