Sin Between Sisters : A Taboo Brother-in-Law Romance #924700

I destroyed my sister for a man who was never mine to keep.
Twenty-three-year-old Elena Martinez made a deal with the devil the night she caught her brother-in-law Marcus alone and aching. What started as stolen glances during morning workouts exploded into a full-blown affair—secret touches, whispered promises, and an obsession that consumed her completely.
She told herself it meant nothing. That she could stop anytime. That her pregnant sister Sophia would never find out.
She was wrong on all counts.
When Sophia walks in on them—the same day her water breaks—Elena's world implodes. The sister who raised her, sacrificed everything for her, loved her unconditionally... now can't even look at her.
Five years later, both women are rebuilding from the wreckage.
Elena is a single mother drowning in guilt, raising a daughter with Marcus's unmistakable eyes. Sophia has found peace with a new husband and the hard-won knowledge that some betrayals can be survived. But when Marcus resurfaces threatening custody battles and fresh manipulation, the sisters face an impossible choice:
Let him destroy them separately, or stand together against the man who nearly broke them both.
Can betrayal this deep ever be forgiven? Can a bond this shattered ever heal?
A raw, unflinching tale of forbidden obsession, devastating consequences, and the brutal journey back to redemption. This is not a love story. This is a reckoning.
⚠️ Content Warnings: Explicit sexual content, infidelity, emotional manipulation, pregnancy complications, PTSD, themes of guilt and forgiveness. Dark romance with bittersweet ending.
"Some loves we borrow and must return. But the love between sisters? That's worth fighting for—even when it's the hardest battle of all."