Dear Therapist: How Do I Deal With My Hostile Sister?

Dear Therapist,

This holiday season, I’ve been navigating some major challenges with my older sister and my boyfriend. The difficulty started last winter, when my boyfriend wanted to buy an investment property in the state where I’m from and my sister currently resides. My sister became very upset with me and my boyfriend for investing in a place where she lives. We received angry phone calls and disparaging text messages from her. We were shocked at her response. I have yet to make up with my sister as she never apologized, but I have been cordial with her when around the rest of our family.

Recently, my sister told our immediate family that she was pregnant. She had previously had two miscarriages, so we were all quite excited. While my boyfriend and I were visiting home, he asked my parents if my sister had told our extended family about her pregnancy. Unfortunately, he was overheard by one of my aunts. We immediately requested that she keep mum, and my aunt never told anyone. But when my sister shared her news with the wider family, this aunt mentioned that she’d already known because she had heard my boyfriend mentioning it to my mom. This resulted in angry text messages from my sister about me “taking her thunder” for this announcement.

I’ve since blocked her on text and social media, but as we head into the holiday season, I’m unsure what to do. My mom is guilting me about my boyfriend not spending the holidays with us, but he doesn’t feel comfortable around my sister.

I would love your thoughts on how to deal with this situation without making it worse, while also protecting myself and my partner from unwanted hatred from my sister.

Dear Reader,

Feeling caught between family loyalty and your relationship with your boyfriend is a challenging position to navigate, especially during the holidays. You’re being pulled between your mother’s desire for family harmony, your sister’s emotional demands, and your boyfriend’s legitimate need for respect. This kind of triangulation is exhausting and can lead to resentment on all sides. The key is to stop trying to be the mediator and focus on transparency with all parties—and then directly communicate what kinds of requests you’re willing (or not) to meet.

To help you figure out the limits you’d like to set, you’ll need to consider the family dynamics underlying the recent tension. What stands out in your letter is how quickly a series of relatively minor incidents escalated into a profound family rift. You say that this conflict “started last winter” with the real-estate investment, but such intense reactions rarely emerge out of nowhere. The vehemence of your sister’s response to an investment you and your boyfriend made suggests that she struggles with unspoken feelings, possibly around sibling envy or competition or perceived abandonment as you spend time with your boyfriend. Sometimes it’s safer to get angry indirectly—in other words, to direct your anger at someone adjacent to the person you’re actually angry with. Your sister appears to be channeling her feelings toward you into conflicts with your boyfriend, perhaps because at this point in her life, she sees your happiness while she feels unimportant, invisible, or overshadowed.

I see this too in her reaction to the pregnancy announcement: She felt that you were stealing her thunder. Of course, for someone who has experienced the pain of two miscarriages, controlling the narrative around a successful pregnancy might feel like one of the few aspects she owns on an otherwise uncertain journey. Even so, your boyfriend didn’t intend for others to hear his question, and you took immediate steps to contain the information—so the fact that your sister hasn’t realized that her reaction was disproportionate to the harm and has made no attempts to apologize for her outburst indicates that deeper sibling wounds are at play.

[Read: Couples therapy, but for siblings]

Meanwhile, your mom is playing an unhelpful role by asking you to make things right despite the way you’ve been treated. Sometimes well-meaning parents try to alleviate sibling tension by encouraging one sibling to take what they see as the smoothest path to ending disharmony without holding the other sibling responsible for her part in creating it. The thinking goes: It’s easier to pressure the more reasonable and adaptable party to accommodate the difficult one than to address the underlying problematic behavior. Your mother might believe she’s promoting family harmony, but in reality, she’s enabling your sister’s behavior while unfairly burdening you with the responsibility for maintaining family relationships.

Your boyfriend, for his part, is entering this family system as an outsider. But if your relationship with him continues to grow, he will become part of your family—and these early patterns of interaction could set the tone for years to come. Your boyfriend’s desire to avoid the holiday gatherings is understandable, but it’s worth considering the long-term implications of this decision. Complete avoidance, while providing temporary reprieve from conflict, might inadvertently cement a rift with your family and make future reconciliation more difficult.

With this context in mind, let’s consider what you might do.

First, with regard to your sister, I encourage you to shift your perspective from “protecting myself and my partner from unwanted hatred” to “understanding and potentially healing a wounded relationship.” This doesn’t mean enduring abuse; instead, it’s about getting to the core of what’s causing it with the hopes of eliminating it. Being “cordial when around family” and blocking communications might reduce immediate stress, but something else needs real attention. Neither you nor your sister has created space for the difficult but necessary conversation about what’s really going on here. Your sister hasn’t apologized or explained her intense reactions, and you haven’t had the opportunity to express how her behavior has affected you and your relationship with your boyfriend. This pattern of avoidance—managing surface interactions while letting the underlying tensions simmer—can lead to exactly what you’re seeing: Each new incident becomes charged with the accumulated weight of unresolved feelings. Until both you and your sister are willing to have an honest, potentially uncomfortable conversation about your relationship, these cycles of conflict will likely continue to escalate.

[Read: What if you just skipped the holidays?]

Consider writing your sister an email that acknowledges her feelings without accepting blame for perceived wrongs. You might say something like “I miss our relationship, and I know that you’ve been feeling hurt. I’m sorry that recent events have created such distance between us. I’m truly thrilled about your pregnancy, and I think these times of transition present an opportunity to bring people closer. I’m hoping we can find a way forward by having a conversation that feels safe and respectful for both of us, with the goal of understanding what’s bothering each of us.”

If she’s willing to do this, you can start the conversation by expressing your genuine interest in repairing the relationship: “I’ve been surprised by what’s been happening between us. I want to understand more about what’s upsetting you in our relationship, and I hope you’ll try to understand how I’ve been feeling too, so we can clear the air and communicate more calmly and openly in the future.”

To your mother, you might say: “Mom, I understand you want everyone together for the holidays, but right now that would create more tension than joy. I know you’d like me to fix this, but this is about something going on between me and my sister—not my boyfriend, not you—so the most helpful thing you can do is to let both of your daughters try to work this out as the adults that we are, no matter what choice gets made this holiday season and no matter what our relationship looks like going forward.”

You can then talk to your boyfriend about how he envisions his relationship with your family, and what steps he feels comfortable taking now to work toward that vision. Perhaps he would feel comfortable attending part of the holiday gathering for a limited time, or participating in some family events but not others. Often, small, manageable steps toward engagement are more sustainable than either total avoidance or forced togetherness, and taking these steps would demonstrate a willingness to engage with the family while still maintaining healthy boundaries that work for him. Remind him that your goal is to support his decisions about maintaining his own limits while ensuring that your relationship with him doesn’t become collateral damage in this family conflict.

Remember that you can’t control anyone’s behavior, but you can control your response to it. If your sister isn’t willing to engage respectfully, you can leave the door open: “I care about you, but I won’t accept hostile messages about me or my boyfriend. I’m happy to have a calm conversation about our relationship when you’re ready.” If your mom continues to guilt-trip you about your boyfriend, you can say, “I know it’s hard to see your daughters not getting along, but I’m done discussing this. Please don’t bring this up again.”

By having these conversations directly with each party, you release yourself of the burden of being assigned to single-handedly fix a complicated family dynamic and allow yourself to focus on a more reachable and healthy goal: making clear, thoughtful decisions that are in the best interest of your relationship with both your family and your boyfriend, even if they disappoint some people in the short term.

Dear Therapist is for informational purposes only, does not constitute medical advice, and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician, mental-health professional, or other qualified health provider with any questions you may have regarding a medical condition.