My dad is furious that my mom slept with other people in an open marriage he wanted.

My parents got married when they were super young. My dad knocked up my mom, and their parents married them off. My grandfather was able to set up some business for my dad in a big city, and they moved here soon after my birth.<br><br>My mom grew up in a conservative southern town where she was taught to be a submissive wife. And even after moving to the big city, she didn't spend much time socializing. She had no friends and never went out. My dad was only there to provide for us. He was always away on business, and he wasn't there as a husband for my mom or as a father to me.<br><br>My dad made a lot of money, so we never lacked anything. Growing up, I became my mom's best friend. We would talk about everything. I pushed her to make friends and to find hobbies. After years of pushing, she started going to a nearby park and made her first friend, a gym trainer. Encouraged by her friend and me, she decided to join the gym.<br><br>She met a couple more people there and started having some semblance of a social life, but she still continued to be a people-pleasing, submissive wife. My dad didn't have any problem with my mom having friends, but he didn't like that she was spending time pursuing hobbies or making choices without him.<br><br>My dad has always been a cheater, and he didn't want my mom straying. But he also didn't want to give up his freedom to bang whoever he wanted. So he asked my mom if she would be up to open marriage. He said he didn't want to cheat on her, but he wanted to explore his sexuality. My mom, being the submissive wife she is, agreed even though she was (and still is) against the concept of open marriages.<br><br>My mom didn't date anyone for a long time. She was still a submissive wife who didn't want to displease her husband. But then I left for college. My mom was lonely, and she met someone. She was too afraid to tell my dad, so she asked me for advice. I pushed her to tell my dad because I didn't want her to be uncomfortable. She finally told my dad, who hit the roof. He said she was too s*** to be sleeping around. He wanted a divorce.<br><br>I came home, and my grandpa and his wife came to visit from out of town. They were furious that my mom cheated. I lashed out at them. I reminded them that my dad had asked for an open marriage. I asked my grandpa why my mom was being judged when my dad was cheating since before they even got married. My dad and his parents want the divorce but want my mom to leave the house my dad paid for.<br><br>My mom wants to stay in the marriage because my dad's family are the only family she knows. My dad's family has been paying for everything since she was a teenager. She is afraid of living on her own. I am so angry and disappointed in my dad and his family. I am planning to stay with my mom, but I am not sure what the future holds for us.