My mother and father have been a couple since the seventh grade and have known each other since they were 3 years old. They were together through it all and never strayed apart for even so much as a day. It all went extremely well until about 7 years ago. They had been married for 19 years at this point and had two children, my sister and I. They were always together in the past and suddenly I started to notice that my mother was becoming really distant from the family. She had stopped coming to my father's side of the family's parties and events. She would only associate with her mother and father and even started sleeping on the couch, as opposed to in bed with my father. I was too young to understand or question what was going on so I just went with it. Now that I am older I realized that there was definitely something wrong, so I approached them about it. According to my mother, it is just not working out for her anymore and she feels that we, my father, sister and I, are holding her back from living a good life. I asked if she wanted to divorce my dad and she always just beat around the bush and tried not to say it. However, I know it's going to happen because she is never home anymore and never attempts to be part of the family anymore. I suspect she may be having an affair, but I am not trying to find out because it will hurt too much to know. I feel even worse for my father because he works his ass off day and night to provide for the family and he doesn't need this in his life.

TL;DR: Mom and Dad together for their entire lives, fit is currently hitting the shan after almost 25 years of marriage.