Dear Amy: My husband’s brother and his wife announced about a year ago that they had irreconcilable differences; they divorced after a long and loveless marriage. To be honest we have no idea why they stayed together as long as they did. About a month later, my brother-in-law introduced us to his new girlfriend. I was initially very happy that he had found someone new who really seemed to fit into the family dynamic better than his ex. But then his new girlfriend reached out on Facebook.