Suddenly Discovered That My Fiancé Was Still Alive

I was heartbroken to see my fiancé pass away. But I suddenly discovered that my fiancé was still alive, and it was his twin brother who died, and he took over the identity of his brother. Next month is his wedding to his sister-in-law, and I plan to give them a big gift. It's just that my stupid fiancé doesn't know yet that everyone but me knows the truth, including his wonderful sister-in-law. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.