When you're married, it's typically for the woman to take the man's last name. She doesn't have to; she can keep her maiden name, or the husband can take her last name. It's just a standard societal custom for the woman to take the man's. But what happens when you divorce? Apparently, it's pretty standard for the ex-wife to keep her husband's last name, especially if they have kids together. And in this story, that is exactly the case. Until the ex-husband's new fiance comes along. The finance…