A few days ago, I found out my sister has been cheating on her boyfriend of several years for the past couple of months. He caught her kissing another guy in August, and she promised it wouldn’t happen again, but she kept talking to him. Based on texts her boyfriend sent me, it’s at least emotional cheating and sexting, though it could be more.
Her boyfriend has become like family to me, especially over the last couple of years. He was incredibly supportive during a tough time for us, and I probably talk to him more than my own family. I know he’s not perfect, but he’s a good guy, always trying to be better for my sister. He’s the only one of her boyfriends I would’ve been happy to call my brother-in-law.
My sister and I have always been close, and I’ve always wanted her to be happy—but not at someone else’s expense. I’m disgusted and ashamed by her actions. It feels like I don’t even know who she is anymore. I never thought she’d hurt someone she claimed to love just for her own pleasure.
The problem is, I live with her. I can’t just get space, and while I don’t approve of what she’s done, I don’t want to ruin our relationship. How do I hold her accountable while also starting to forgive her?
Here’s what you’re feeling: heartbreak, betrayal, confusion, and maybe a sense of helplessness. You’re mourning two things at once—the loss of trust in your sister and the loss of someone you’ve grown close to. This is deep, man. It’s not just about her cheating. It’s about your entire worldview shifting. Someone you thought you knew, someone you trusted, made a decision that shattered that trust.
First, let’s get this straight—you are allowed to be angry. You are allowed to feel hurt. Your sister’s actions were wrong, full stop. She betrayed someone she claimed to love, and in a way, she’s betrayed you too. It’s okay to sit in that discomfort for a moment. Acknowledge it. Don’t brush it under the rug.
But here’s where it gets tricky: You live with her, you care about her, and despite everything, you still want to maintain that relationship. That’s where grace comes in—not for her benefit, but for yours. Holding onto rage will eat you alive.
Now, accountability doesn’t mean you explode on her or make her feel miserable every day. Accountability is about honest conversations. You sit her down and say, “I love you, but what you did hurt people. It hurt him, and it hurt me.” You let her know the impact of her choices, but you also leave room for her to grow, to own up to it. People can’t change unless they recognize the damage they’ve done.
Forgiveness, though—that’s a journey. It doesn’t mean you forget or excuse her actions. Forgiveness is about freeing yourself from carrying this weight. You can love her without approving of what she did. But understand this—it’s okay to create boundaries. You might need some space emotionally, even if you can’t get it physically.
At the end of the day, relationships are messy, and people are complex. Your sister made a choice, but that doesn’t mean she’s beyond redemption. And here’s the truth: this is a moment that will shape both of you. You have to decide how to navigate it with honesty, compassion, and yes, some boundaries. Keep the conversation going, but don’t be afraid to step back when you need to.