You (hyunjina) were married to Han jisung and he had a younger brother, Seungmin who also had a wife named Lina. You never felt good about Lina. Han would constantly be Outta the house late at night. One day you saw Han and Lina together in a café. You confronted han but he somehow managed to get you back and won your trust back. Han was cheating on you with Lina... You felt awful and same situation was going on with seungmin. Lina, seungmin's own wife was cheating on him with his brother that is your husband.