In the years observing MEM and their dysfunctional mothers, I have found that most mothers are divorced and they openly live with their sons as partners.
However, should mother still be married, there are only two types of husbands I have observed.
One is the emotionally absent husband or partner. The partner who does his own thing, who will have settled into his own life separate from his partner. Who will have friends he sees and talks to, emails and has intellectual conversations with, but his wife is nowhere emotionally close. He does not trust his wife with his feelings and neither does he want to hear about her feelings. He might listen a bit but has no empathy for her and her struggles. He would rather go fishing with his friends or read a book than to spend quality time with his spouse, meaning an emotional discussion where one is vulnerable. He will refuse to be vulnerable and refuse to see her in a vulnerable stage. He'd rather leave with some excuse. He is comfortable. He does not want to be emotionally close to his wife and he encourages their son to be close, to take care of mom, to keep her happy, to listen to her and follow her command. If the son dares to go against mom's orders, her control, the father will be upset and set the son straight. It is his responsibility to make mom happy. The son is in a rock and a hard place. Both parents expect him to serve mother, he has no refuge, nobody to understand his frustration he is not allowed to openly vent. Only this father is not needing to have control. He lets mother and son do their thing, he just doesn't want to be part of anything. He wants to be left alone and is ok guilt tripping his son into being the mother's partner. He gets a lot of praise for catering to his mom from his dad, the only acknowledgment he usually gets from his emotionally absent father.
As we were preparing for a family reunion on my MEMs side, we live 4 hours away from his mother, his father asked how my MEM's mother is going to get to the reunion. We didn't know. His reply: You will have to go pick her up and bring her to the reunion.” I was stunned and stammered: “But we have 5 children and I am pregnant, we are pulling a trailer, and I don't want my husband to drive 8 hours when there are plenty of others without children who could pick her up.” He replied authoritative: “It is her son's responsibility to pick her up and make sure she gets to the reunion, nobody elses!!!” It was clear that his father made my MEM responsible for his mother's happiness. They are divorced but only on paper, emotionally she is still married to him and is under the control of her narcissists ex-husband.
The other extreme is the husband is a narcissist. He too is emotionally absent but he has a strong need for complete control. His family cowers whenever he roars, even if they have been adults for decades. Whatever dad says is doctrine for the family. Dad's expectations need to be met, no matter how old you are. Nobody dares to stand up to dad. Not the wife, not the children, not a sibling, not a in-law. If anybody married into the family dares to question how things are done, they are immediately cut out from the family. The son or daughter is still allowed into the family but it is clear that the spouse is no longer tolerated. My MEM's family had a brother who routinely came himself to reunions because his wife knew she was no longer tolerated. She started planning things the same time the reunions were scheduled to be in order to be away and to make her spouse have to choose between her and their children and his parents and siblings. If he picked his own family, his siblings and parents all attributed it to the wife who just can't stand having him get along with his family of origin, yet alienating the wife further from the reset of the family. The husband never corrects this thinking because he doesn't want to hurt his family of origin and most likely he feels the same way. His spouse is keeping him from participating fully in all the activities of his family of origin. He too is upset about it, which makes him repeat the cycle of mother enmeshment. He becomes emotionally distant from his wife and she turns to a son to fill that void.
The narcissist controls the movements of his children and wife right up to his death. He demands complete obedience without questioning and he receives it because the wife and children have been trained to not make him upset. He is the one who sets the rules of who is in good standing in the family and who isn't. A spouse of the MEM will never be in good standing, the spouse messes up the dynamic and questions the complete obedience and needs to be kept away from the closed circle of the family unit. She is and will always be an outsider. Her motives will be construed and twisted to further the feeling of this spouse being trouble and just wanting to break up the family, control, and demand without merits. Everybody buys into it and the spouse of the MEM in the family will never have support within the family. In my case not even the in-laws dared to speak up against the narcissist father in law. They would mention something behind closed doors but never say anything in front of anybody else in the family nor would they admit to ever having said anything. The spouse of the MEM is alone in her fight to simply have her reality acknowledged, to have someone else say you are correct, the rest of the family of origin is crazy but not you. They all march to the beat of the father's drum, you realize the drum is out of tune and makes them march into more destruction and misery.
There is no winning being married to a mama's boy. You will always be the evil outsider who needs to be fought. No matter if your in-laws are divorced, if the father is emotionally absent or if he is a narcissist, your experience is the same, you are an outsider who is viciously attacked from all sides, emotionally, verbally, and spiritually abused and kept at a distance. There is no making them understand the dysfunction, you are alone and trapped in a loosing battle.