Best Books About Betrayal By Sister In Relationships?

Scarlet’s world shattered the night she discovered her husband in her bed with her own sister. The betrayal was brutal. The humiliation, unforgivable. And what hurt the most? Neither of them felt a single ounce of remorse. Within months, her husband divorced her and married the very woman who helped destroy her life, her sister. They thought she would break. They thought she would disappear quietly. They were wrong. Ryan Marchetti—cold, calculating, and dangerously powerful, has spent years waiting for the perfect chance to destroy his business rival. Marrying that rival’s ex-wife is the ultimate move. Strategic. For Scarlet, marrying Ryan isn’t about love. It’s about revenge. A calculated alliance. A public statement. A promise that she will rise from the ashes they left her in. Together, they become the scandal that shakes empires. But revenge is never simple. Because behind Ryan’s icy control lies a secret, one tied to her past, to her ex-husband, to the very marriage that ruined her life. A truth so explosive it could unravel everything she thought she knew. Was she just a pawn in Ryan’s war from the very beginning? Or is the man she’s slowly falling for capable of betraying her too? In a game fueled by vengeance, power, and buried truths, Scarlet must decide: Will she let betrayal destroy her again… Or will she risk her heart for the one man who might truly love her?

Violet's world shatters the moment she walks into her own living room and finds her husband tangled up with her stepsister. The man she loved. The sister she trusted. Both betraying her in the most humiliating way possible. Now, with her marriage destroyed and her heart in pieces, violet vows to take everything from them …her husband’s empire, her stepsister’s peace, and her own power back. But when a mysterious billionaire, Liam Knight, walks into her life offering partnership and passion, violet finds herself torn between revenge and the chance to love again. Will she burn her enemies to ashes… or risk her heart one more time?

On the night of my engagement party, I found my fiancé with his hands in my sister’s hair. I thought the betrayal ended there. I was wrong. Minutes later, Ethan stood in front of both our families and announced that he was in love with Ava. My sister. While everyone rushed to comfort them, I became the villain for refusing to smile through my own humiliation. Then Damien Black walked into the room. Powerful. Untouchable. The one man Ethan feared. Before the night ended, Damien handed me a contract. One year. One marriage. One chance to save my father’s company. All I had to do was become his wife. I should have said no. Instead, I signed. Now my ex can’t stop watching me. My sister can’t stop competing with me. And the man I married keeps protecting pieces of me I thought nobody noticed. The problem is that Damien Black is hiding something. And every day I spend with him makes me less certain that our marriage was ever supposed to be just a contract.

On my wedding day, my arranged fiancé abandoned me and chose my sister instead. As I became the laughingstock of every elite guest in attendance, my business partner James Crawford shocked everyone by publicly proposing to me with a passionate declaration of love. After we married, he was incredibly attentive, especially during my pregnancy when he catered to my every need. I thought my suffering had finally ended. Until I overheard his confession to my sister: "I've only ever loved you." James's voice carried a passion I'd never heard him use with me. "Marry her? I was only after her resources, connections, and her talent for making money. She's nothing but a useful cash cow." "Now that she's pregnant, even better." His tone was coldly calculating. "With the baby, she'll be even more dependent on me, more devoted. She'll never leave." Everything I had treasured—our love, our marriage—was all a lie. Learning the truth, I turned and walked away without a word. I was done with this charade. Everything that belonged to me, I would reclaim with my own hands.

I had stopped pretending the night Sebastian sailed past our bedroom door for the third time and didn’t look back. I had married him to keep my father’s company intact. Out of my father's desperation. The vows were for the cameras and the board, everything else was ledger entries and quiet compromises. He chased his affairs in public while I held the facade. He saw my composure and called it martyrdom. He never figured out that my calm was armor, not devotion. Then Samantha came home, twenty-three, luminous, curious, the kind of warmth that made places in me I’d kept cordoned off ache. She drifted into my life with easy laughter and careless questions. A sister-in-law, that became my obsession. We started with late-night talks, her voice soft in an empty house, her hand brushing mine while we pretended we were discussing nothing at all. Those small touches stopped being accidental, but deliberate. While Sebastian was busy elsewhere, I took his sister. Not to win anything on a balance sheet, not to score a victory, but to finally have the means to protect who I am, and who I love. Samantha was bewildered at first, shame and curiosity tangling on her face, but the way she leaned into the moments we stole told me more than words ever could. It was messy and urgent and selfish. She became my refuge and my ruin. The tenderness I had once sold to survive became a liability I was suddenly proud to bear. When the scandal around Sebastian crescendoed, I didn’t hide behind the marriage or the name. I stepped into the light, shoulder to shoulder with her, exposed and fierce. I traded anonymity for that, truth wrapped in possession, and I, Mikayla Stonefield, would have done it again.

She thought his heart belonged to her, but he chose her sister. Adriana Nox found her sister moaning beneath the man she was supposed to announce her relationship with. The strong Adriana Nox broke at that moment and never healed. She watched the man she had ever loved exchange vows with her sister, a disaster she never imagined would happen. Not only was she betrayed by the ones she loved, but declared a villain and cast away by the same people she trusted. But Adriana swore never to go down into the pit of fire alone. She would drag everyone down with her, including her beloved sister and the love of her life. Note: This is Book 2 of The Nox Bloodline Series. It can be read without the first book of the series, as it is a stand-alone. But for a deeper understanding of the characters, you are free to check out Book 1 of The Nox Bloodline series. Book 1: Lycan Brothers Want Me Book 2: Betrayed By My Lycan Sister, Became A Villain