close an interaction, or dismiss a notification. Telltale signs of toxic, narcissistic in-laws and how you can learn to deal with them -- dismiss a notification. in laws stress in laws stress [5d777f0c6f24eb28784f4153?width=600&format=jpeg&auto=webp] NEUMIARZHYTSKI VALERY / Shutterstock * Narcissistic parents-in-law are incredibly cruel, often going out of their way to make sure their son or daughterʼs spouse doesnʼt feel welcome, according to trauma therapist Shannon Thomas. -- * Sometimes they are wise to it, but itʼs still incredibly hard to deal with their mind games. * For example, narcissistic in-laws will play favorites, isolate the target from their own children, and lie about anything to fit their narrative and make the target feel excluded. * Narcissists often act like theyʼre reading from the same instruction manual, so there are some telltale signs that a toxic in-law is what youʼre dealing with. * Visit Insiderʼs homepage for more stories. Imagine marrying into a family and realizing your mother and father-in-law are hellbent on destroying your entire life, relationship, and self-esteem. It may sound like the plot of a psychological thriller, but toxic, narcissistic in-laws are a reality many people live with. "Narcissistic in-laws are incredibly cruel," trauma therapist Shannon Thomas told Insider. "Everybody wants to be a part of a healthy, fun family, but when you are the target, with that sense of belonging and -- not." Narcissistic in-laws can ruin a marriage, Thomas said, especially if the son or daughter is oblivious to the games their parents are playing. Thomas said itʼs probably because they are in denial about the -- Narcissists often act like theyʼre reading from the same instruction manual, so there are some telltale signs that a toxic in-law is what youʼre dealing with. Narcissistic in-laws like to play favorites It can sometimes take grandchildren to be in the picture for the narcissistic in-laws to show their true colors. For instance, in one family Thomas knew, two grandchildren had the same name. -- "The cruelty is youʼll see them be very close to some family members, and they will definitely bring some in-laws into the fold," Thomas said. "Itʼs because they like the family members that are most like them." -- "Especially if theyʼve not made an attempt to be like them," said Thomas. "If the in-law has continued to stand in their own independence, thatʼs when they really attack." -- For example, a woman recently sent an absurd and disturbing letter to The Cutʼs "Ask Polly" column, where she explained that her in-laws refused to stop serving her mushrooms even though she is deathly allergic to them. Read more: A woman told an advice column that her in-laws wonʼt stop serving her mushrooms despite her deadly allergy, and a trauma therapist thinks it could be a sign of toxic narcissism -- Youʼll notice a lot of mean behaviors Other games the narcissist in-laws play include: * Planning a trip and only inviting the targeted spouse a couple of days before. This way they can say "we invited them, they just -- She said itʼs important targeted partners realize they are not the distorted version of themselves the narcissistic in-laws are painting them to be. To remind themselves of their worth they should spend time with friends and put boundaries in place with how, where, and when they -- NOW WATCH: More: Narcissists Parents In-laws Mental Health * toxic people * Lifestyle UK