Annie gave four years of her life to Diaman James, only to watch him destroy everything with a single betrayal. Pregnant by a reckless mistake and married to another woman, Diaman leaves Annie heartbroken and determined never to love again. But fate has other plans. When Grey James, Diaman's powerful elder brother, proposes a fake relationship to escape family pressure, Annie sees an opportunity for revenge. What begins as a simple arrangement soon turns into something far more dangerous as real feelings emerge between them. As Annie fights to rebuild her life, dark secrets begin to surface. Betrayal, manipulation, kidnapping, hidden identities, and shocking family revelations threaten to destroy everything she has left. Meanwhile, Diaman discovers a devastating truth that makes him desperate to win Annie back. Caught between a painful past and an uncertain future, Annie must decide whether to return to the man who broke her heart or trust the one who helped her heal it. Married To My Ex's Brother is an emotional billionaire romance filled with betrayal, revenge, fake dating, forbidden love, family secrets, and unexpected twists.