5 Red Flags That Indicate a Toxic Relationship with Your Mother-in-Law, According to a Clinical Psychologist

Family dynamics are notoriously hard to navigate—especially when the family in question isn’t your own. Let’s be honest, ‘strained relations with mother-in-law’ is practically its own genre of drama—and comedy—in movies. On a more serious note, though, overtly negative behaviors from a MIL can have a serious impact on the health of a romantic relationship and, if gone unchecked (or even inadvertently validated by a partner), can leave you feeling isolated and undervalued. Without further ado, here are five red flags that can indicate a toxic relationship with your mother-in-law, plus some very sound advice from a clinical psychologist as to how you can respond if such behavior rears its ugly head.

Dr. Bethany Cook, PsyD, MT-BC, is a licensed clinical psychologist and author of For What It’s Worth: A Perspective on How to Thrive and Survive Parenting. She's a sought after therapist and quoted media expert who brings accessible, real-world guidance to families of all socioeconomic and mental health backgrounds, based on over 20 years of clinical experience in the field.

Passive-aggressive comments are one of the hardest toxic behaviors to confront, because they’re intentionally designed to hide under the guise of humor or seemingly neutral observation. They come in many different forms and can crop up in many different contexts…yet, you’ll likely recognize one as soon as it lands. The problem is that, although ostensibly humorous or innocent, “such remarks serve as covert ego deflations. They employ social comparison and internalization to gradually undermine self-esteem, instilling persistent feelings of inadequacy and chronic self-doubt,” explains Dr. Cook. Toxic indeed.

• Example: You mention how next month you want to start meal-planning to minimize food waste and stop ordering in so frequently. MIL chuckles and says: “It’s okay, not everyone can be as organized as I was.”
• Recommended Response: Dr. Cook says that your best bet is to “address the comment directly by asking, ‘I’m curious—what do you mean by that?’ because this response prompts clarification while signaling that you will not tolerate veiled criticism.” (She also notes that this response might encourage your partner to offer supportive validation.)

If your MIL uses comparison as a means to validate you and lift you up (think: “You juggle so many responsibilities. If I had to do the same back in the day, I don’t think I’d be nearly as good at it!”) then I’d call this one a green flag. Alas, in toxic relationships with a MIL, it’s likely that comparisons are reliably unfavorable. (A not-so-loving love language, if you will.)

There’s plenty of room for overlap with the passive-aggressive red flag here, but regardless of how they slip out, Dr. Cook says that “such comparisons are analogous to evaluating a modern smartphone against a rotary phone—namely because they disregard the substantial differences in context and individual circumstances. This outdated benchmark fosters an internal critic that convinces you that you are continually falling short, despite modern challenges.”

• Example: During a discussion on household management, or even just as a passing comment, the toxic mother-in-law might state, “When I was your age, I always kept the house spotless,” implicitly suggesting that your current efforts are substandard.
• Recommended Response: Respond by stating, “I appreciate that things were different in your day, but I am managing modern challenges in my own way.” Encourage your partner to support your approach, reinforcing that progress should be measured against current realities rather than outdated yardsticks.

No one likes to work hard for what they want only to have a close relative take the wind out of their sails. According to Dr. Cook, “This minimization functions like a pair of glasses that continually blur your accomplishments and erode self-worth by reducing the intrinsic satisfaction of success, thus creating a disconnect between the effort expended and the recognition deserved.” And it’s a pretty big red flag, since this toxic behavior can diminish your motivation to pursue further achievements over time.

• Example: After sharing news of a well-deserved promotion, the mother-in-law comments, “That’s nice, but I remember when I was doing similar things—it wasn’t nearly as challenging for me,” thereby diminishing your achievement.
• Recommended Response: Assertively express, “I am proud of my achievement and would appreciate celebrating it together.” Then, request that your partner actively acknowledge your successes, thereby fostering an environment of mutual recognition and support.

This one is a solid red flag that serves to undermine you individually and before your partner. And speaking from personal experience, it becomes especially problematic when kids are involved. (Think: “Little Johnny needs to finish all the food on his plate or he won’t grow big and strong!”) Or in Dr. Cook’s words: “Such unsolicited advice often conceals a desire to control and subtly undermines your autonomy. It implies that you lack the capacity to make sound decisions independently, thereby challenging your self-efficacy.”

• Example: Upon revealing a new decorating choice, the mother-in-law might interject, “You know, I always chose neutral colors when I redecorated—it just works better,” implying that your aesthetic decisions require safeguarding.
• Recommended Response: “Politely, yet firmly, respond with, ‘I appreciate your suggestion; however, I am excited about and confident in my own ideas and choices.’” (And, as always, encourage your partner to get on your team, too.)

This is called stonewalling, friends, and it’s one of the four horsemen of the relationship apocalypse, according to The Gottman Institute (and verified by many lived experiences). If you’re used to your MIL chiming in a bit too much, you might be surprised to experience this sudden shift towards silence as so, well, negative. But there’s a reason for that: “This non-verbal withdrawal is equivalent to a mic drop with no follow-up; it leaves tension unresolved and disrupts healthy communication. Such silence breeds uncertainty and can erode trust over time,” explains Dr. Cook.

• Example: Following a disagreement—such as over holiday plans—the mother-in-law may suddenly withdraw, becoming emotionally silent and leaving the underlying issues unresolved.
• Recommended Response: In a calm and assertive manner, say, “I’ve noticed you seem distant, and I value open communication. Can we discuss what’s bothering you?” For extra support, it’s also a sound idea to ask your partner to facilitate a dialogue that bridges the communication gap and resolves lingering tensions.

There are no guarantees that you can change your MIL with healthy and open communication, but it should be your first line of defense. Be sure to set good boundaries and maintain them in order to keep conflict and tension to a minimum. And if communication with your MIL isn’t working out the way you want, remember that, at the very least, you should be able to have that mutual understanding with your partner. In other words, enlist your partner’s help when navigating this tricky situation; if they consistently refuse to show up for you in this situation, you might need to start turning your attention to red flags in that relationship.